If you are taking a typical FIRE approach of broad-based mutual fund investing in primarily retirement accounts, you are not itemizing, and you don't have rental or business income, I don't think a tax preparer provides significant value. For the most part, you can sit and wait for your tax forms to roll in, and file yourself at a free online tax filing company. I'm personally fond of freetaxusa.com, and it is pretty much an exercise in data entry. Sidenote, I always thought the name made it sound like a scam website. Terrible branding, but great product!
I also think there is value in understanding your personal tax situation and crafting your own plan for savings and investments. First, most inexpensive options for tax professionals aren't going to give you advice fitting someone whose goal is retiring 20-30 years earlier than most. Second, there is value in understanding your own situation beyond the monetary (greater likelihood of adherence to your plan, less concerns about being ignorant of an aspect of your life you are seeking to optimize, etc.). Finally, I've found that with enough forethought and prior research before asking a question, this forum has provided all of the answers I've needed.
However, I do think that if you can find a professional with some strong chops who would sit down and walk through some forward thinking tax planning, there may be some value to be extracted in minimizing your tax burden going forward.