Since most people who check out Bloodborne will be veterans of the Souls series, I will focus my review on comparing the features implemented in Bloodborne to its spiritual predecessors. In short though, there are too many design flaws, and this is the weakest Souls game I have played thus far.
For instance, the fact that you can't teleport between lamps, and must first go back to the hub is one such flaw, especially considering how absurdly long the loading times are. I can't help but feel that they tried to copy Demon's Souls too hard without actually weighing the merits of old features that Dark Souls clearly improved upon. As others have mentioned, lots of other poor quality of life features like having to farm vials & bullets also exist in the game as a result of From's crude nostalgia of Demon's Souls.
The disturbingly few types of equipment, magic and dumbed down attire system (can't be upgraded or lose durability) also made the game severely lacking in variety. Nearly 80% of all players I run into are using either Ludwig or Chikage, and everyone appear nearly visually identical. There is for the most part only a single playstyle now, with half-baked features like magic merely adding to the playstyle in small ways. This in turn destroys replayability of the main game at least. Other features are simply the same features made to look like something else, namely the personal rune system which is really just rings with unlimited durability, and weapon runes merely offer static upgrades like regular upgrading, or offer effects similar to what enchants in Dark Souls would do.
Oh, did I mention that there are only three PvP covenants in the entire game now? No PvE covenant whatsoever. A double back roll compared to the numerous interesting covenants presented in Dark Souls 2. I can't help but feel that the amount of content was intentionally restricted in early phases of the game's production. It's as though Bloodborne was never designed to be as big a game as its predecessors, and that's reflected in the lower average "hours to beat" (Google it up), especially for completionists (difference up to 50 hrs).
Finally, the endgame in Bloodborne took a completely different and quite unwelcoming approach. In previous Souls games, to get the best gear you either have to improve covenant reputation (usually involves MP) or play through the game a couple times. In Bloodborne, the best gear (cursed gems) are exclusively found in Chalice dungeons. Random MP is nearly entirely out of the question in randomly generated dungeons. Getting good cursed gems also depends a massive lot on RNG, so the endgame grinding is quite comparable to grind-heavy ARPGs like Diablo 3 instead of traditional Souls games.
Ultimately, Bloodborne feels like 70% of what a Souls game should be. So much has been taken out, and so little added in. I only see myself enjoying a single playthrough and then I will move onto something more worthwhile, including Dark Souls 2 Scholar of First Sin. I falsely expected a lot more longevity from a Souls game, but in retrospect I wish I rented the game instead of buying it.