"There is no war but class war," and these layoffs are 100% class warfare. There are a few factors going into this, but the short version is that capital wants labor to suffer because labor is making too many demands on capital, and capital also hates inflation (while inflation is better for labor in the long term).

First, we have high employment. This drives wages up, despite resistance from capital, and also ensures that labor has mobility- you can walk out of your job and have a reasonable chance of finding a new, similar job, probably with better pay, in a short time. (NB: this is not true through all sectors of the economy, and so I'm not trying to describe the conditions as they are in their entirety, but the perspective capital is bringing to the table.)

The other side of high employment is that it drives inflation- inflation being "too much money chasing too few goods". Inflation is terrible for capital, since it eats away at their fortunes. While inflation raises the cost of living for labor, it also encourages debt leverage (high inflation shrinks your debts relative to the cost-of-living). A mortgage becomes a better deal, because inflation is basically a negative interest rate- but it also becomes a bad deal for the banks. (NB: "too much money chasing too few goods" can be solved by increasing production, but that requires investments of capital and speculation- due to finacialization, capital is no longer used to produce anything but more capital, not goods, so they're attacking it on the money side.)

So capital wants to put labor back under their heel where it "belongs". The fact that this round of mass layoffs are in the tech sector (as opposed to anywhere else) are driven by a few factors.

First, your big tech companies went on a hiring spree over the past few years, motivated by a mixture of having huge gobs of cash and also a desire to lock talent into their business and deny them to competitors. Plus, with an attitude of skunkworks/startup culture, it also meant that each hire was a gamble with a low percentage payout of having the next great new product come out of them. So big tech is overstaffed relative to their actual operational needs (but not relative to their incomes).

Second, these jobs are considered prestigious and lucrative. Mass layoffs in the tech sector are a great way to send a message to the general public: you are not safe, no one is safe, even the most privileged among you answer to capital. Get back into line, plebes.

Third, companies at the scale of Apple and Google have billions in cash on hand- they're not businesses, they're financial institutions. (NB: Apple is avoiding layoffs because they didn't overhire and are so focused on vertically integrating that there's less leverage for investors to drive Apple's behavior.) Capital has enjoyed reaping the rewards of these companies, but they're also eyeing the wealth that these companies represent: they want the golden eggs now, and are tired of waiting for the goose to appreciate in value. Capital wants to demonstrate that they control these companies, can drive their actions and leadership, because capital wants to exercise its power over all industries.

Expect more rounds of layoffs, and expect a lot of the big label tech brands to start faltering and get eaten in the next few years. First off, layoffs are bad for companies and reduce their overall health. Second, a lot of highly experienced talent hitting the job market at the same time is going to create a lot of competitors. While the near term, your Googles will have the warchest required to purchase competitors before they become a real threat to their bottom line, that's a strategy with an expiration date. We're witnessing a realignment of the tech sector on par with the Dotcom bust.