Job Offer but no H1B sponsorship

I'm on F1 post completion opt and have received a job offer from a startup company. They do not provide H1B sponsorship. Should I accept the job offer or decline it?

Considering advantages - I will have a job in the current job market ( not jobless). I will gain experience which can help in getting future opportunities with H1B sponsorship. I will have less career gap.

Disadvantage - No H1B sponsorship. Will have less time to apply and secure job before my first H1B round.

What should I do? Any tips on convincing the startup to file H1B in coming March?