Surprisingly complicated question. Most hobbyist grade machines are low powered and can only cure resin with pretty poor mechanical properties. Industrial resin printers can actually make incredibly strong parts. The studio 1 can apparently print in Formlabs Tough 1500 which is a decent strength resin. It’s noticeably better than the average “ABS like”. Resin prints are also isotopic (unlike composites and fdm prints) which has a lot of advantages for mechanical parts. Asking if resin prints are strong is a bit like asking if metal parts are strong; it really depends on the metal or resin being used

Resin is generally very stiff but also very brittle. They are not as tough as composites (depending on resin used).

My experience is the resin is very stiff but very brittle, but I haven't kept up with the latest resins.