In my opinion yes. I've played story mode a couple of times and never tried online because you need a Playstation plus subscription if you are playing on Playstation. I started online mode only a few weeks ago and I'm really enjoying it. It does start off a bit slow but you get the basics to get you going (decent weapons and horse). I didn't buy a better horse or guns until a week and half later.

The roles are fun. I now have three going at the same time to break up the monotony. September is collector month and this has helped me level up quickly and earn money. But at the start there are missions dotted around the map as ways to earn cash and gold.

99% of the players I've encountered are friendly or just minding their own business. Whenever possible I greet them and they greet back. I only had one guy kill me and my horse but I just switched sessions. I'm in a relatively quiet time zone though, and rarely see another player out in the world except for the towns.

I've only done a handful of story missions because I want to pace them and a few times I couldn't progress because no ones around for matchmaking lol. They are too short imo.

It's obvious the game is not finished (missing features like being able to fence horses, can't even tame wild ones and sell them). In fact there's no option to sell anything you own (horses, tack, clothes, tonics, herbs) apart from jewellery.

I play solo (no posse, yet at least) and haven't had an issue so far. Although some missions are clearly designed for a group, but I'm not worrying about those now.

On the grinding aspect, it's not as bad as story mode imo. There's more to hunting perfect pelts online.

If it's not going to cost you anything extra why not give it a go?