I first used Canva ages ago, then generally let it lapse in favour of a more powerful graphic design package (Gimp). However, I tried it again recently and was very impressed, especially for the ease of creating presentation slides and pdf workbooks / brochures etc. Canva have done a really nice job with ease of use and you can make some really nice results, even on the free plan. I haven't tried the premium options.
There are limitations to what you can create with the free plan (for example, last time I checked, transparent backgrounds weren't free), so don't abandon all your other tools just yet. I also see (for my liking) far too many affiliate promotions for Canva, so I'd suggest you use it extensively before you hand over your credit card.
Someone with moderate design skills who needs a tool that's easier than Photoshop, InDesign etc.