I was hoping that other English speakers would contribute, because I didn't really want to get into a meta-argument about using the forum either. To me, yes, there are things that can be irritating, but maybe it's just better not to respond than to criticize until the criticism also becomes irritating.
I agree with Martin that there are many other possible responses to 'Thank you.' I would just say that the warmer, more traditional ones may come across better in a text-only context like here in the forum or elsewhere online, where you can't see a smile or any visual expression. In fact, I might easily add a smiley online.
You're very welcome.
You're quite welcome.
I'm (so) glad you liked it / them.
It was a pleasure.
I was happy to do it.
I was happy to be able to help.
It was fun to put them together.
I actually enjoyed doing it.
Belatedly, I would caution against reading too much into social media users claiming to teach 'real' English, when what they're really sharing is the English of their own age group, cultural demographic, and social class. They may not even be very experienced in politer, older circles, where 'You're (very / quite) welcome' is still entirely correct and friendly. So please don't believe anyone who urges you to avoid it.
There are other more casual responses that could come across as brusque, flippant, or just less polite when used online, without an accompanying smile. Just adding the period for punctuation, to me, makes them look a little more polite.
Glad I could help.
No worries. (chiefly AusE?)
I'm not crazy about 'That's okay,' since it doesn't have any rational meaning in this context. And starting with the word 'no' can come across as kind of a brushoff, even expressing impatience or disinterest, toward someone you don't know well, so those are all in the 'less polite' category.
On the other hand, between some friends, perhaps especially guys, it would be typical to play down both the favor and the thanks for it, to avoid anything that could sound gushy or soft. So online too, it will depend on the type of group.
I would also not read anything into using or avoiding the word 'you,' since careful users of English still know that it's either singular or plural, so there is no need to use anything less polite when addressing a group.