When people say "ChatGPT" it's important to clarify if they mean GPT-4 (paid version), or the free GPT-3.5. GPT-4 is a completely different level, it's miles better in every way. It's like comparing a 10 year old to a 20 year old.
I got the impression that they gimped 3.5 severely over time. Since 4 is still restricted to 25 messages / 3 hours (for paying customers!), I sometimes fall back on 3.5. Of course it's impossible to prove, but it feels like it's failing hilariously at tasks it could do easily a few months ago. I wonder if more people have this suspicion or if it's just my imagination?
I didn't copy a reference, just been reading AI topics on HN lately.