For stock images, I saw some reviews that mentioned Envato is lacking in that department compared to the likes of Adobe and
Pexels 
I'd disagree about Pexels. Nothing bad about them but they look like a crowdsourced clone of Adobe Stock but with way less stock images, sometimes even Unsplash has images more related to the subject matter than Pexels, and sometimes I have trouble finding certain topics on any free stock image host.
If you want to have images for
every possible topic including very recent events, Getty Images is the go-to source, but they have a hefty price tag outside the range of everybody but by news corps, and only per-image licensing becomes feasible ie. royalties (which itself puts you at a net loss if the royalties are bigger than your ad revenue).
