Yes, PlantUML is very helpful in that way. I know this because I have used it in many projects. But Mermaid caught my attention because of its beauty and simplicity. I don't know if you have tried to customize a PlantUML diagram with colors, positions and other stuff. I don't have the patience for that. :p
Now, UML is a recognized standard, and it will not go anywhere. If you learn it, you won't waste time at all.
So, I rather prefer mermaid for personal or small projects which don't involve many people. However, if you need to diagram for work in a large company with established standards, then UML is your friend here.
In the end, we have options, and we pick the best tool for every job.
Good luck!
I voted "Yes", but I meant "Yes, to use LSP without blocking the whole thing everytime".