Good to hear you plan on starting your own business. Lots of tax benefits. You can max out 401k on both employer and employee sides, if you set up as LLC taxed as S Corp, you can pay yourself a defensible salary and take remaining profits as distributions which aren't counted for payroll taxes, you get 20% QBID (unless Congress lets it lapse in 2025), etc.

Regarding RMDs, depending on your current age, those may not be retired until age 75. Also, if you own no more than 5% of your employer (including 0%), your 401k with that employer isn't counted toward RMDs as long as you're on payroll (at any income level and any number of hours worked). You can potentially roll all other 401k accounts and all IRAs into that 401k and not have to take any RMDs.