The main thing that I have read from those that disagree with my premise is that abilities have so little meaning that they can hardly recall their stats. Let me help you, your primary was a 20. What this means to me is that there are too many feat/ASI bonuses and using them to max out your primary stat has basically become a feat tax. That doesn't sound like fun to me.
As someone who has been nodding while reading those arguments, and occasionally giving them XP, I can tell you that the bolded text is flat out wrong.
Maybe your players overwhelmingly max out their primary stat. Good for them. I know that I've had only 1 character in the last 15 years of gaming with a maxed out primary stat, that wasn't for a one shot dungeon delve. Or rolled stats, because the force is strong with me sometimes. I've had 2 or more 18's in one set of rolls probably a half dozen or more times.
But every time we point buy, whether it's been 3.5, Star Wars (RCR or Saga), 4e, 5e, or D20 Modern, neither I nor anyone in my group tries to max out their main stat. In 5e, we'd much rather take feats, most of the time. I've got one guy who obsessively spreads out his points, for instance making a kobold wizard with a 14 starting Int, and then makes sure to take feats (like linguist. real powergamer, this guy) that boost his main stat, or use ASI's, to keep his accuracy from flagging, but really that isn't even necessary in 5e. He'd be fine to boost the main stat with one ASI, and then forget about it.
My one maxed out stat guy? Half-elf Bard, Swashbuckler, bisexual casanova, son of a legit Fey Prince and a Traveler woman gorgeous enough to catch his eye and interesting enough to keep it for a while. So, yeah...max Charisma wasn't exactly a choice of stats over roleplaying!
My Halfling Ranger in our Eberron game started with 16 dex after race mod, and his first feat is Ritualist. Because 4e and 5e both, via different means, make it easy to use point buy to moderate your scores and be decent at a wide range of things.
But some people like to specialise, and...I really dont' understand why that matters to you? Why is it a problem for you that other people are building their character the way they want?