TBH I'm surprised to find that most of these never were singles.
This. Though trying to outdo citoyen in being in the wrong topic, weren't there less singles at the time and/or a decision to release an album without singles?
In the UK, The Beatles sometimes released an album and a separate single, recorded in the same sessions, at about the same time. So, I Want to Hold Your Hand came out a week before With The Beatles, I Feel Fine just before Beatles For Sale and Day Tripper on the same day as Rubber Soul.
Hey Jude was recorded during the sessions for the White Album but came out while that was still being recorded and, infamously, Penny Lane and Strawberry Fields Forever were the first tracks recorded for Sgt Pepper but were lifted for a single under pressure from the record company as it had been
a whole six months since the previous release. (There's probably a whole web site devoted to arguing about which two tracks could have been left off Pepper to make way for their inclusion).
Lesser artists would quickly scour the single-free albums for potential covers and have hits with them themselves, hence both Michelle and Ob-la-di Ob-la-da were number ones for others at the same time as The Beatles' own versions were still freshly minted.