I replayed Mafia 1 and 2 just a jew months ago and the first one is still one of my favourite games of all time, it's still great today because of its atmosphere, the mission variety and design, ofc the story but also the gameplay, while a bit janky at times, is good and has a lot of depth to it.
Also, I remembered the game to be a lot harder and more frustrating but, maybe because I already know the game maybe because I was 12 or 13 at the time, it went a lot smoother this time and I died way less. But still, I think the fact that you have to plan your moves carefully because every mistake may cost you half your health (or all of it) works in the game's favour overall.
Mafia 2 is something I'm more conflicted about. On one hand they simplified more than a few things and the combat is that of a pretty generic tps, on the other hand you can still see that the devs were passionate about the game and add a lot of nice little details wherever they could (car fixing, skipping lockpicking minigame by shooting the lock with a gun, two different wanted levels, etc.) and they definetely nailed the atmosphere, the setting and also car handling.
Also, the story had a strong first half but then it was pretty obviously rushed in the second part of the game. Sadly, that's the big problem of the game: it's incomplete and it shows, if 2K didn't force the team to rush it I think Mafia 2 could've been a great game.
I didn't even played the third one but it seems a very generic and an overall mediocre GTA clone, while previous games had their own identity that made them stand out compared to GTA and its imitators.
And since this Mafia 4 appears to be made by the same devs that made the third I don't exactly expect much from the game, although I'd love to be proven wrong. But I don't think I will be, not until Vavra and Warhorse decide they're done with Medieval Bohemia and start making a spiritual successor to Mafia, at least.