I don’t think anyone has said you’re doing it wrong if you just call for the skill. You’re doing it differently than what the rules describe, but there’s nothing wrong with that.
Well that’s not what it means according to the rules.

I live in the US and it isn’t too much work for me.
Well, yeah, it would be when the default is strength. The advantage of calling for the ability instead of a skill is that there doesn’t need to
be a default.
That’s why I would call for a “Charisma check” rather than a “Charisma plus Intimidate check”. That’s actually less specific than “Intimidate check” because there are eighteen different options the player can substitute (or more if you include tools), compared to the 6 they can substitute if you call for an “Intimate check.”
People certainly don’t need to run the game the same, and if just calling for a skill check works for you (as it does for many DMs, I might even say the majority of DMs), great. I’m not telling you you can’t or shouldn’t do it that way, I’m just explaining why I do it the way I do, because people seemed confused by it and have been asking a lot of questions about it. Advocating for my preferred method is not an attack against your preferred method. They can co-exist.