They may be able to be refinished.

It depends on how many times they have been sanded before.

And it may depend on whether they have wax on them. If all of the wax
is not removed it can cause probs with any polyurethane finish that you
apply now.

I had a 75yo house whose floors were trashed. I had not taken care of
them during a 15y renovation. My current H refinished them (it's his
line of work) and they looked absolutely beautiful.

So there is hope.

And it generally costs less to refinish them than most people supposed
so you might want to get some estimates.