I don't know about steam but if you look at the twitch numbers (which probably correlate more with esport from a pro/money perspective) CSGO does look to be declining since its peak in 2020[0] (which I'd wager was due to some huge event or the pandemic) and is consistently less popular than Valorant.
Apr. 2020 was peak daily players, 857k, the exact month Valorant Beta was released. They're trending down to 563k as of the last 30 days, down 34% in just 2 years. Valorant is posting 1.5m and has only been trending upwards. Maybe "dead" is exaggerative but long term trend is clear with Riot's compared to Valve's stewardship.
I have no idea how you can come to that conclusion based on that data.
valorant is too new of a game to tell, overwatch was pretty big back in the day too
apr 2020 was peak daily players because of lockdowns.