Never made or can't remember making UML diagrams, what are your opinions on them?

Meh, it was a moment totally hot 15 years ago. UML everything! UML is fine I guess, if you need it. What's the alternative? Not making diagram and describe in a text file?

The last time that I made or read a UML diagram was in uni, more than a decade ago.
Nobody needs that shit in practice.

I do like making diagrams. I just don't care about what "type" they are. Kinda just mix and match the best fitting boxes... Though I guess UMLs are the one exceptions where I do like to keep up with the rules because it kinda makes sense?

I don't make a lot of them, nor are they usually exactly necessary, but they can help here and there

Need them regularly. Different scenarios, but I'm thankful for many diagrams that stopped me from re-implementing or maintaining the wrong components.
If you don't need or use them, your team and product are both very small. The larger the team or product, the more likely you are to have such diagrams. Also package dependencies are a nightmare to figure out without up to date docs. (Again, unless the product is small)

Also, even your hand drawing of components technically is a UML diagram. The notation is not as strict as it used to be like 15 yrs ago.

I’ve used it about twice professionally (for database design) and regretted it both times. It is time consuming and you’re not actually left with much of a product. Best thing to do is to create the database and let a DB tool generate a diagram for you, if you really need a diagram.

The practical problem with presenting a complete UML diagram to a manager is a manager only cares about the “important” tables, so you’re really just better off making a custom diagram that only shows the core functionality.

The in depth nature of UML isn’t necessary, but being able to take things from it and use it in real life scenarios can be helpful. For example, I’ve used my own abridged version of UML before to help visualize some spaghetti in a legacy codebase.

I think the important lesson about UML is that you’re just learning one method for visualizing a high level design.

UML is simultaneous too complex to quickly sketch something and too simple to achieve it's ultimate goal (automatically generating code from it)

It's fine I guess... Nobody actually does UML correctly anyways. But if you know you're not doing UML, you might aswell just ditch it and do whatever makes most sense to you ¯\_(ツ)_/¯

I use them a lot less than I expected. Mostly for data communication protocol designs.