The matches themselves are not rigorous. It's the fact that they played the most matches, went to every tournament, then on top of that Shahz in particular is probably the most consistent streamer out of any pro player, the whole team also is flying from Texas to LA to film content for Sentinels and then also flying to wherever they're from to visit family. If you're just viewing it from the angle of "only 3 international tournaments in 2021" then of course it seems light.
For your second point I guess it depends what you want to get out of your esports career. Streaming is essential to building a brand that lasts past your playing days. If you want to be able to provide for your family in the long term (in Shahz's case this includes his mom who is now widowed because his dad died from COVID) then it's probably more important than pro play honestly lol. At the end of the day pro play in Valorant is not currently setting you up with generational wealth. Streaming has the potential too.