Apple's iPhone lineup is the weakest it's been in years - and it has everything to do with the iPhone XR

Two years ago, in 2017, Apple had an iPhone for every size and price point.

The iPhone SE was the smallest and most affordable phone. It had a 4-inch display, and started at $350.

The iPhone 6S and 6S Plus — two great phones — started at $450 and $550.

The iPhone 7 and 7 Plus — two of my favorite iPhone designs ever — started at $550 and $670.

The iPhone 8 and 8 Plus — the pinnacle of the iPhone 6-era phones — started at $700 and $800.

Then Apple had the iPhone X, a top-of-the-line phone with futuristic features. That started at $1,000.

And so, in one year, Apple had iPhones ranging in price from $350 to $1,000, making it easier than ever to find an Apple smartphone that was right for you.

Two years later, the iPhone lineup is a very different story. It's not as diverse or as straightforward.

The 4-inch iPhone SE is gone, unfortunately, which means you can no longer buy a new iPhone from Apple for $350. The smallest and cheapest phone Apple sells is now the 4.7-inch iPhone 7, which starts at $450.

Here's why Apple should bring back the iPhone SE.

The iPhone 8 and 8 Plus are still around, and they now cost $600 and $700 to start. They're the same size as the iPhone 7 and iPhone 7 Plus.

The next size up is the $1,000 iPhone XS, which has a 5.8-inch display. It's really nice.

Want to go bigger? Apple has the 6.1-inch iPhone XR. It's actually $250 cheaper than the iPhone XS, starting at $750 — but its display, while bigger, isn't as good as the iPhone XS.

Finally, the biggest phone Apple offers is the 6.5-inch iPhone XS Max. It has the same excellent display quality as the iPhone XS.

When you look at the current iPhone lineup, the quality of the phones tends to get better with size. But the iPhone XR is the exception: It's sized between the iPhone XS and XS Max, but it's not better than either of those phones — it's simply more affordable.

Here's why you should buy the iPhone XS instead of the more affordable iPhone XR.

The reason Apple's 2017 iPhone lineup was so successful was because each phone was the best possible device at its price point. The iPhone SE was the best 4-inch phone. The iPhone X was justifiably more expensive than the iPhone 8 Plus, with its bigger and better display.

Now, if you want a phone around 6 inches, you can't say the iPhone XR is better than the iPhone XS, despite its bigger screen. You'd think Apple would make the best possible phone for any given size, but the iPhone XR is intentionally inferior in order to fit a price point.

In short, Apple sells fewer new phones than it did in 2017, and choosing isn't as straightforward as it was then. Bigger phones don't translate to a better experience anymore: The iPhone XR is inferior to the iPhone XS, and lots of people find the iPhone XS Max is just a bit too unwieldy in general.

The Verge has a good breakdown of the iPhone XS Max's size.

You could argue that the iPhone XR — with its superior battery life, color options, and entry price — make it more appealing than the iPhone XS. But its display is a turnoff every time I see it in person, and since that's what you'll be looking at all day, it's difficult to recommend this phone over the smaller iPhone — which is a rare thing to say about Apple phones. Moving up in size usually doesn’t mean a drop in quality, but that’s the case with the iPhone XR.

The current iPhone lineup hasn't clicked with customers. On January 2, Apple warned that it was expecting to miss its original revenue targets for the all-important holiday quarter; CEO Tim Cook blamed most of the revenue lapse on sluggish iPhone sales.

Aside from China, Cook blamed weak iPhone sales on "consumers adapting to a world with fewer carrier subsidies, US dollar strength-related price increases, and some customers taking advantage of significantly reduced pricing for iPhone battery replacements."

Cook also said "iPhone upgrades were not as strong as we thought they would be" in some developed markets.

You can read Tim Cook's full letter to investors here.

Business Insider also conducted a recent poll, which said one out of every three iPhone owners in the US chose not to upgrade because the new iPhones are either too expensive or they don't have enough compelling features.

You can read the full results from our survey here.

In many ways, the iPhone XR is creating confusion like the iPhone 5C did back in 2013. The iPhone 5C wasn't as good as the iPhone 5S, but they were the same size — and since both phones debuted at the same time, most people chose to buy the better option.

The iPhone 5C failed. It was discontinued after that year, while the iPhone 5S lived on for years after in the form of the iPhone SE.

If Apple wants to reinvigorate the current iPhone lineup, it should consider a $100 price drop across all three new phones. A $650 iPhone XR is an easier pill to swallow for the step down in screen quality, while the iPhone XS and XS Max would be a little cheaper to match the lower demand for these phones, which aren't very different than the prior-year iPhone X.

Here's hoping the 2019 iPhone lineup is a little more straightforward, and does a little better to accommodate every size and price point like the company did two years ago.