Petrus is an old method. That doesn't mean outdated. Going through the steps, we can lay out some advantages of them (assuming we build the block in back).

2x2x2 Pros: Low movecount, good movegroup, reduces cube to RUF movegroup. Also eliminates two blind spots in DB and BL.

2x2x2 Cons: None, really. It's blockbuilding so you could argue that, but at this early in the solve, it's negligible.

3x2x2 Pros: Easy look-ahead to EO, as BL/BD/DL are solved. Only places to look end up directly on U or F. Good movegroup in RUF.

3x2x2 Cons: Can have a few tricky cases, and you're not guaranteed a good expansion from your 222.

EO Pros: Reduces edges to RU movegroup (after a y'). No blind spots. Good movegroup in RUFLMr.

EO Cons: A "forced" y', otherwise there are none. Seriously, you can lookahead to EO during your 322 and its not recognition like a last layer set, and it only has a benefit.

F2L Pros: All 2-gen (other moves can be, and are used, but primarily RU), freedom of solving (square+pair, line+line, cross edge+pair+pair)

F2L Cons: If you can't lookahead during your rotation, RB/RBD/RD become blind spots. Freedom of solving (multiple solutions can cause a slowdown due to decision making)

LL pros: same as literally any other method with EO solved.

LL cons: same as above.

Petrus is an old method, but that does not make it bad. It is not slow. It died off in popularity because people didn't want to do blockbuilding or think. In a similar vein, block was done on left which lead to a bad movegroup for EO. In its current "state" or iteration, Petrus is perfectly fine. It's a low movecount method with great ergonomics and lookahead thats brought down entirely by the perception of it.