It's certainly not the best route for everyone, but definitely one worth considering.
I think being a founder is a great option right out of school--if you are working for yourself, responsible for your own mistakes, and not actively harming anyone else in your quest for personal achievement.
Bad managers (and most bad management - from death marches to protoduction - can be boiled down to "makes the people who report to them pay for the manager's mistakes") exist even in supposedly mature companies with good corporate cultures.
What's good for your personal growth was other people trying to make a living at a company being run by people who don't know what they are doing. Maybe it's fine, but that level of uncertainty is definitely a con.
Luckily we mostly had temporary interns as employees, and I can confidently say that they had a good experience, as we are still in touch.
The biggest problems of the inexperience were that we had to ramp up our skills on the job (for me programming), including the mistakes you make there, which killed a lot of the runway, and the lack of business knowledge which ultimately lead to us running out of money.
The rest of the startup game - building a product, pivoting correctly, building a team, overcoming oowerful rivals - is such a huge challenge, that gaining entry level experience before finishing school is perhaps the most straightforward piece of the puzzle.
Anyone can start a business, and anyone should. The things you mentioned - "pivoting" "overcoming powerful rivals" - goodness. How about simply starting a business that earns more money then it spends. Do that and you will learn most any lesson you need to know about being a "founder."It's possible to build "boutique" scale internet software businesses, but it's harder than ever, and you still need to be well-off enough to "risk" some time that you would otherwise be working on definitely-getting-a-paycheck type work.
In short "start a profitable business instead working for one" and "start a business that's profitable right away instead of taking VC funding" are both rather useless pieces of advice for somebody who doesn't have the means or background to do either.
There are of course more choices about what to do with your life. You should explore those too. Maybe you'd be happier as an auto mechanic or a nurse. That kind of work is available almost anywhere in the country so you won't have the "three body problem" of having to live away from your or your spouse's family, or both.
I'm not sure what you are defining as risk or difficulty. I can list a dozen day-one-profitable businesses right here that a person could start before tomorrow morning for less than $100 investment.
Too tough?
Spend $100 on a Beaver Builder license. YouTube to learn. You are now in the small business website building service.
Too tough?
Call a business and tell them you can help their local SEO for a price greater than $20/month. Once the check clears, get them an Advice local account. Pocket the difference.
Too tough?
Call a local business and tell them (true) that 92% of all visitors will seek out their business in a second source other than their home page. For $100 you will setup their Facebook page. For another 100 you will train them to post to it and reply to reviews.
Too tough?
Call a local company and tell them you can handle their social media strategy. If they have T, FB, LI, and IG then great. If not then charge 100 to build them. Signup for Hootsuite. Post to their accounts for the entire week on a Monday morning.
Too tough?
Call a small business and tell them that the number one way to generate repeat business is through a regular email newsletter to previous customers. Sell for $250/month. Signup for Outbound Engine agency program. Profit.
Too tough? Call a business and tell them that chat tech on the front of their site can increase lead flow by as much as 11x. Signup for Apex Chat account, charge $20 per less. (Apex charges you $10)
On and on. It's never been harder to start Facebook or Amazon or Google because we already have Facebook and Amazon and google. But divest yourself from needing approval and applause and you start to see one big truth: its really really easy to make a lot of money online.
Can you expand a bit on the "harder than ever" point? I've observed a couple of phase changes since the 90s, but I don't think I've seen that particular needle move very much in the past ten years.
Easier said than done. Lots of people leave school without the faintest clue what they want to do. Getting a job somewhere gives people training and experience and maybe even credibility before they strike it out on their own.