A startup exit doesn't simply erase all its impact. Plaid made many banking services a lot easier & popular, and it demonstrated how valuable that can be. All that doesn't just disappear. An acquisition/merger can also strengthen a startup's founding ambitions with more resources at its disposal.

Can, but often enough, it doesn't. We end up with a cancelled product/service, or one maligned beyond recognition by the acquirer, with users having to untangle the service from their lives at last minute, while acquirer holds all the IP.

Also, I question the general usefulness of startups created to pursue an exit in the first place. Besides there being often no point in entangling yourself with a service that's meant to be transient, the goals will be different too - the company will try to force hypergrowth by underhanded, and ultimately user-hostile means, vs. letting a thing grow on the strength of its usefulness. Myself, I strongly avoid dealing with any startup that I can smell was built for an exit.