Tech is still valued as growth stocks compared to other sectors. If you look at the EPS, its trending down and growth is negative.[1] That's not "doing great" for what most investors expect out of a relatively mature tech stock that doesn’t pay a dividend. In other words, why would I pay growth-stock valuation for something that isn't growing its earnings?

(obviously, the analysis is more complicated than this, but you can see why investors may not think things are going gang-busters over at Meta)

[1] https://www.macrotrends.net/stocks/charts/META/meta-platform...