After two decades' worth of false starts and declined pitches, it's still amazing that this game finally gets to exist. Perhaps it's even for the best that it took this long, as the developers it landed with seem to understand and care about what makes a success in the now-niche field of beat-'em-ups.
Case in point: today Streets of Rage 4's first significant update goes out to all platforms in the form of a balancing patch. The individual gameplay changes are numerous, but they generally fall under buffs for player characters and nerfs for enemies. Can't say I'm mad at that. The netcode is supposed to be improved as well.
The developers have also stated they plan on adding content to the game. While they haven't gotten more specific than that, I can think of three bosses off the top of my head that are just begging to be made playable, so hopes are high.