Think of the origin of laïcité in France. Religion - in the shape of Christianity - colluded with aristocracy in oppressing the people. Hence Diderot, "Et ses mains ourdiraient les entrailles du prêtre,/Au défaut d’un cordon pour étrangler les rois." ('And his hands would plait the priest's entrails, for want of a rope to strangle the kings', often simplified to "Strangle the last king with the guts of the last priest".) And, well, 1789; "Allons enfants ...!"
OK, not so violent nowadays. But a ban on public religious practice and symbols takes the place of that in enforcing the shutting-out of (essentially oppressive) religion from public life and society.
Now, of course religion still oppresses. Although there is a complicated mix of respect for autonomy, counters to historical and imperialism-based racism and so on and so on, it is undeniable that many religions - in particular the Abrahamic - are sexist to their patriarchal socks. And the French ban on oppressively-based sexism-determined clothing says, simply, "This State - our commonwealth - is thoroughly and definitively against such oppression and sexism".
Where should we stand on this? We are against sexist oppression. But we are in favour of personal autonomy. So something of a dilemma, indeed. Is it possible to be anti-racist, anti-sexist, and still in favour of personal autonomy in the light of such historical and continuing oppression? Of course. But (tldr:) it's complicated. Tricky, like much ethical choice.