Depends on the kind of job you're looking for, and as you age your needs change in a way that erodes your leverage.

I don't think ageism has anything to do with experience or knowledge as it relates to technology, quite the opposite in my experience, particularly in established enterprises where stability and adherence to process is valued above all.

A 50yo with a mortgage and kids in college will take abuse for years from the leviathan conglomerate that a 20-something wouldn't, simply because they have to.

This is where age becomes a culture-fit thing so you need to target those (mostly undesirable) organizations. All the leviathan cares about is that you're not too close to retirement such that they can recoup their investment in on-boarding you.

A startup or turn-around story on the other hand would prize adaptability and inventiveness, so that culture tends not to be a fit for people later in their career with one eye on the clock and where comp trumps equity.

If you were a fit for a GREAT job, why are you coming in off the street after having 20+ years to build relationships/value? You should have enough connections by now that you're constantly being hounded to fill executive or mercenary roles from the best people you've worked with in the past, not debasing and commoditizing yourself to strangers on LinkedIn.

Coming from enterprise tech myself I see that very few people understand this. It's downright sad to see old friends and colleagues chasing down the latest industry certifications like the next one will turn things around. It demonstrates an insecurity over their reputation and what they can prove to buy the same sheepskins a rookie would in-lieu of actual experience.