It's not about sex being done to women - it's about how if there is no choice to abort an unwanted pregnancy and you do not want to have a child, it is sensible to avoid engaging in activity that risks pregnancy. There are other sex acts - and given how many women are engaging in sex where they don't orgasm, probably not that much would be lost to them.
The reasoning is not so much to convince the real anti-abortion hardliners - you won't, in any way - but to firstly protect yourself and to secondly, by means of a 'strike', to provide an actual direct incentive, a personal loss, to piss enough men off to also take a definite and active agitation for abortion rights, not only vague support
Obviously if you're not in a country where this applies, there's no point to it. No point a woman in the UK taking part in a sex strike for US women or Polish women or women under any other jurisdiction.