Clearly teaching got a lot better, since we now have a new teaching tool at our use, the LLMs. It's evaluating that got harder, because students can use the same tool to cheat in traditional forms of evaluation.
If "teaching the students" means the same as "evaluating the students" to you, maybe you shouldn't teach in the first place.
It’s like copy-paste Wikipedia presentations 2 decades ago. People used to learn things doing research for a project. Then suddenly it became copying off Wikipedia and people not even pre-reading what they copied into PPT.
Even devoid of all the economic and social pressures that grades impose students would compromise their learning experience. Ever regretted looking up the solution to a puzzle in a video game or sneaked a peak at the crossword puzzle solutions?
One of the hardest part of teaching is keeping students from self-sabotage. Evaluation helps with that.
Beyond that evaluation is of course also useful just as feedback.