I'm genuinely asking, I'm a simple software dev not a doctor.
And bacteria self-replicate, whereas a virus needs to infect a cell and be reproduced by that cell. Some antiviral mechanisms attack the reproduction proteins that the human cells use, which the virus cannot do without. And the human cells don't have reproductive pressure to replicate viruses, quite the contrary.
I think the biggest difference is that bacteria can react to a treatment, while viruses don't have the capacity to react. If you've stopped a virus from replicating, it's essentially dead. A bacterium may have defensive measures it can take. It could form an endospore and try to wait things out. If you've stopped it from reproducing, as it ages it might start accumulating free radicals that increase DNA damage, leading to a higher chance of it mutating to resist the antibiotic. Etc.
Bacteria also swap genes between themselves [0], whereas two viral particles sitting on the same Petri dish are too inert/simple for that. That represents an additional way for adaptive tricks to spread.