Most of the VC open-source projects use open-source as a lead magnet/marketing tactic only, with no intention or desire of wanting people to actually use the software.
There is a distinction between those companies who actually license their stuff under FOSS licenses, but use it to get more marketing/contributors/whatever, and what companies like Meta are doing today, which is calling something "open source" in their marketing material, but if you read the terms and conditions, they call it "proprietary" instead and comes with lots of restrictions that aren't compatible with FOSS.
One is a marketing tactic, the other one is outright misleading.
One is a marketing tactic, the other one is outright misleading.