Everyone thinks sole founders are less likely to succeed than co-founded business, however the actual stats are inconclusive.
It looks like the number one reason startups fail is due to founder conflict. While at the same time sole founders on average take longer to build bigger businesses.
Having done both, for me the big thing is about sharing the experience with someone.
Typically it is less stressful and more enjoyable when you’re in it with someone else, plus it’s normally easier to raise money with co-founders.
Find a friend
I would always recommend you try and find a co-founder, even if you are a a couple of years into the business.
It will make it easier to scale as one of you can run the business, while the other leads the investment round. If you have co-founders you spread the load and the business won’t go on pause when you are raising.
Two brains are almost always better at solving a problem. Two diverse brains are even better still!