"Who could be right, the multiple designers who do this every day..."

Those designer might actually be very good one's but they might have different goals. Their design might be all about eye pleasing hoping that mos potential customers will glance at it, like it and buy it. Ergonomics might not be their concern at all.

There are other UX designers though, making GUI for pilots, nuclear station operators etc. etc. They have somewhat different goals. I feel that my brain digests what they do way better then the stuff coming from a first group

I come from a different background where I learned to value reaching the goal in most clear and shortest way