All I can give you is an anecdote.

My oldest son graduated college in 2019. The original plan was "live at home until you get a job and save enough for an apartment". We figured 6-9 months. He got a job, but that job started having him travel from New England to North Carolina for 2-3 week work trips. Didn't make much sense for him to get an apartment that would be sitting empty anyway so the "plan" was put on hold until the travel stopped. Then the pandemic hit. Travel stopped but now there was new uncertainty about job security. He was eventually set up to be a remote employee (data analysis) and we basically abandoned the "plan" in case he was the victim of "let the new guy go" or "we're shutting down".

He's still working remote and living with us. On weekends, he drives about an hour to visit friends he's made through work and stays with them for the weekend so they can all do stuff together. We don't charge him for rent, food, or utilities.

In 2020, he bought a new car. That's also the year he paid off the last of his student loans. The car is 90% paid off and he pays for his own car insurance. He also gives us $40/month towards our cell phone bill because he's on our plan. Outside of that, he banks everything else.

He's been contributing the full $6k towards his IRA since 2019. He's also contributing to his company's 401(k) to max the company match but not the full contribution max. He also has an emergency fund that is about a years salary that he is working on transitioning to I Series bonds. He decided to go for a year as a starting point because his first job out of college didn't pay as much as he had hoped. He's going to leave it at it's current dollar amount as he gets better paying jobs so that it gets closer to the standard 3-6 months expenses. He's now at the point where he has money coming in that he has no immediate need to spend on anything. Next year will be the first year he is on his own medical and dental coverage through work so that he can start contributing to an HSA. Once we get into the new year and see what his paycheck is like with the new deductions, we'll sit down and talk about what to do with the money including consideration of maxing out his 401(k) contributions.

We get along with him and he helps out with stuff around the house as needed but also has his freedom to go and do whatever he wants. He knows when meals are served and if he's not going to be around, we just ask that he let us know so I can either cook less or plan on what to do with the leftovers. He's welcome to stay for at least another decade (my expected retirement) and personally, the longer he stays, the better the financial foundation he'll build so the lower the risk that he'd ever need help after moving out.

Hope this helps.