Between like 2012 and 2022, pay and benefits for engineers at tech companies in the US skyrocketed. This was for a lot of reasons and it is not something that investors and management like.
Starting in 2022ish, tech companies started feeling pressure from investors to control costs at the same time that the covid-era froth was dying down and the economy was becoming more unstable. The first round of layoffs pushed back against over-hiring. But by doing this together, tech companies managed to halt (and somewhat reverse) the growth in compensation for employees. Regular small layoffs since then have kept the hiring market awful, so companies can hire for less and offer flat pay across time.
These layoffs are part of a broader reaction by capital against the power gains that labor made over the past decade (especially during the covid era).