Is it better to completely replace kitchen cabinets or reface them?

Depends on a lot of things.

Is there any kind of water damage? Are the cabinets made of real wood or press board or composites? What would you replace it with? The same? Or something better?

The list is endless.

I’d just buy new ones.

If the kitchen is just getting an update then keeping the old frames works.. If you want a whole new Kitchen best to start with a clean slate..

Neither is necessarily better than the other
Depends the look you want.
Both are a lot of work

If they are spacious enough or you got attached to them, you could just reface them.

Mine are solid wood with beautiful grain. It would be crazy to not strip and re-varnish them.

Replace them all with a bag of holding.

Depends on your cabinets

It depends on the condition.

Reface

Refacing will be much less expensive. The busted drawer can be fixed or replaced. One cabinet that can take a beating is the sink base. If you want to share some photos I can tell you more.

I've done both--it all depends on what effect you are after and what money you want to spend

I'd think it depends on the shape of what you have now and how they are sized.

show us a pix if you want

Replace