I started and run an e-commerce company, and my best advice before starting a business is to think very little about what you want your product to be and a whole lot about what you want your lifestyle to be.
Want to have relaxing end-of-year holidays? Don't start a B2B SaaS company in which you're going to close a huge % of your yearly revenue in the last few days of the year.
Want to be able to travel? You're probably better off with an internet business than a brick-and-mortar store.
Want to be able to eventually step back? You need to make sure that there's a path to lessening your involvement over time without hurting the business.
I started mine during the pandemic and got it to profitability. It's not world-shifting money, but it produces solid cashflow. At that point, rather than trying to raise money and aggressively scale, I automated as much as I could. Got a manufacturer to make the products. Found a 3PL to handle fulfillment. Went through all the common types of support emails I got and made sure those questions were addressed proactively in the product or emails, so I get basically no support emails. Handed off bookkeeping to a professional.
Some of that has changed (the 3PL was terrible and for now I'm doing some fulfillment myself and using Amazon for the rest), but overall I'm only spending a few hours a week on the business. I write marketing emails, ship some product and place orders for stuff as needed.
The really nice thing is that I can move things on or off of my own plate as my workload changes. I'm working a full time PM job that I'm loving, and my wife just had a baby, so I might offload the marketing emails soon (but honestly they're super quick and I often just reuse last year's, so that's tough to justify). If I leave my job, I could definitely move manufacturing in house to expand margins.
I think more than anything, it's those qualities of the business that make it great for me (definitely more than the product).