I think a lot of how things were 2-3 years ago will not be the same nowadays, seeing how Steam market has drastically changed. It will be harder to get noticed as an unknown developer nowadays than it was back then. My first commercial game (not the very first game I made as I made some free games first) was Atonement: Scourge of Time.
It was first released at the end of 2014 and early 2015 on other marketplaces like Desura (which is now bankrupt), Indie Game Stand (which is also gone now), Greenman Gaming, etc. It was on Steam greenlight for a good 6-7 months before it was approved and released in summer of 2015. My next commercial game (Incitement 3) went through greenlight faster, and things got some traction with every new title afterwards. I'd say Atonement 1 did pretty well overall. It's still selling to this day, albeit not huge amounts, and most on big discounts, but people are still buying it here and there. And same goes for my other older games, like City of Chains, which was received really well.
The good thing is that with every new title you release, you also draw attention to your older titles. If people like one of your games, they're likely to check out the others too.
It's a lot riskier now to be a start up indie dev, as getting noticed is more of an uphill battle than before. You could still have a go at it with a smaller game project and see how it fares before deciding if committing to a larger project is worth it. But a lot of factors could make or break your game's success - the visual style you use, the gameplay premise, the price you set for it, how good your trailer and screenshots are, the total length, and even the timing of release.
Regarding a publisher, I'd say only go for them if they really have a significant influence and can get your game noticed, and so that they don't take a huge cut (or worse, an upfront fee). I've been working with a publisher whom I met here on the forums since I went commercial but ended it very recently. He's had much more connections than me and worked with a few other game devs too, so I could concentrate more on game making. I've enjoyed working with him, but things are quite different now in the market, and small-time publishers have almost as little influence now as the devs themselves, so it might not be a good idea even getting one now.
Anyways, I hope this helps.