I’m surprised too looking at how many subscribers he has! I don’t think any of his vids have ever been in my feed either… wonder why.
They’re especially good for mainstream stuff like iOS and frontend dev, especially frontend because it is such a fast-moving topic - with new frameworks or libraries appearing every other day 
for instance there are some that have just come out for Svelte (posted here) - so you end up with fairly recent (up-to-date?) resources.
The Microsoft ones on JS were excellent too, and it was great that no ads showed at all.
They’re definitely worth a look for frontend stuff imo 