I support open borders (yes open borders) because I support human rights. Migration is natural and human. Limiting migration limits people's ability to improve their circumstance. Closed borders also limit society's ability to benefit from migranta because they are stuck in an unproductive situation.

Nope it is not. It is an explanation for why you see it. You said you can’t understand why people are not trying to prevent new people over entering the tech labour market in US.

They simply see that the longterm gain for everyone is higher by having more people do high-value creating jobs vs the shortterm strategy of pulling up the ladder after yourself.