DavyCDs3 and Elden Ring feel nearly identical but if you think for example ds1 and sekiro or blood borne feel or play the same you are just lost
sekiro is the only one that is noticably different. all the games have differences in how they feel and play, but its the same exact system. the same strategies work, the weapons have almost entirely identical movesets, even enemy types are directly copy pasted with little to no changes. i think ive fought the asylum demon 4 times in elden ring alone. bloodborne isnt as samey as the rest, its just slightly faster than other souls games and has a vastly different setting and aesthetic. past the gimmick of weapons transforming they are also the same by and large
the level designs are also extremely similar. theres a poison swamp, a magic cave, a large castle, a village or town thats been devastated by some force, sometimes multiples of them. these areas also have similar threats inside, to the point that when you enter these areas you know what to be on the lookout for your very first time through even going in blind, just from playing the previous games.
you can easily play all souls games in the same way with the exception of sekiro, even then spacing and dodging enemies can work just not as well as parrying/pressure. the only thing in bloodborne you cant really do is tank with a shield as effectively as you can in souls.
the games in general add very little between installments and they reuse massive amounts of stuff, if you took someone that hasnt played the games or has played very little and dropped them into a random souls game they would have no concrete way to tell what game they are in without trying to judge graphical differences or if they had seen parts of the game from streams or videos. hell even the controls between all the games are basically 100% identical with small changes here and there (not talking about kbm)