I find your second sentence very difficult to pull off in practice, if you have any sort of responsibility (e.g. kids). Modern interviews seem to assume you have a lot of time to dedicate to prep.

In the old days, one could prep while on severance. But those seem to be becoming. Less generous and in some cases being skimped on through shenanigans.

Don't prep by doing leetcode. Skip leetcode places and places that expect multi-hour homework assignments as part of the interview process. Doing so narrows your options, but does not eliminate all openings. (In fact, I consider both leetcode and homework assignments to be negative signals about the company, or at least the team, so this can be a net win.)