No, the drysuit, and also sidemount are in my opinion the 'could be usefull' courses. Not required, but can be usefull. So I don't see that they are useless, but they are not needed for every diver.@Germie is the drysuit course not necessary? I’d heard the taught you how to pull out of an uncontrolled ascent due to shifting bubble, which seems important
Maybe it takes some more time to learn it yourself, but also that is not always true if you go with an experienced buddy.
You have the usefull courses like open water, advanced open water, cave, trimix, ccr.
The could be usefull courses like drysuit, sidemount, deep diver, but also an fundamentals/intro to tech.
And you have the just for fun or if you are interested courses like photography, biology, boat diver, etc.
If you want to follow the 'just for fun' and the 'could be usefull' courses I would advice you to go to someone that really practise what they preach, so really a sidemount diver, really a photographer, really someone who has affinity with underwater biology. Not an instructor that is just allowed to teach these courses.
So this said, I am not against such courses, but they are not usefull for every diver. And I share the avelo under the same. For me not needed, for others maybe usefull. So you know yourself best to know what works for you.
I got my drysuit cert with buying my first drysuit and have never seen an instructor. Here it is quite normal to buy a drysuit and don't do a course.
I am an instructor, but I am against just selling cards. If I teach, I want to have motivated students and want to be motivated myself too. I don't like it if people sell courses just to make money. And this means that if someone without a sidemount cert wants to start technical diving we do a 'let's know each other dive'. Then I know if the diver is able to handle it. But for a drysuit I have never asked for a cert, it is no requirement and I have never seen people here who cannot handle a drysuit if they sign up for a techcourse. Also for example courses like intro to tech are not required. For some I would advice them, for others not. I see enought divers who are able to start tech without such a course (and I see dives who I advice to do such a course).