What's driving "One More Year" besides being risk averse?

I am (and for sure partner and I together) are FI with the following stats:

• total NW (individually): ~$4M

• taxable accounts: $2.1M

• tax advantaged accounts (none of this is ROTH): $1.1M (I did NOT do a good job at this in my 20s hence why this is so much lower than taxable - was like, what's an IRA? only opened it when i was 30)

• all my investments are essentially in equities with approximately 300K in cash

• home equity: $0.8M

• annual expenses in my non-retired form: ~$80K

• + partner's NW of ~$3M and unknown annual expenses though not much outside of his car + tools hobbies

• 41, no kids, no plan for kids

• likely inheritance since my frugal single mom who never made more than 100K has also managed to amass a small fortune and is barely spending it despite my coaxing her ($1.5M)

Here are the things holding me back from FIRE - i am curious if other OMYs are in similar boat or for those who managed to get over it, how you did!:

• shifting things from all equities to a more diversified portfolio: this sounds like a lot of huge tax implications which will immediately have impact on my NW and doesn't sound like fun! not something i'm super interested in researching in contrast to contributing to VTI which is just easy peasy. I am also reluctant to pay someone else to manage this for me.
• understanding the tax complexities and strategies in early retirement: linked to above, this also sounds like a lot of planning to deal with
• unknown of how what expenses will be in RE: my ~80K expenses does not take into account ACA or taxes; i will have to invest time to model out exactly what my expenses would be in RE given i will be paying taxes (linked to point above - tax complexities... doing some light research on this it seems like we could be paying 0 taxes if done right) and needing to buy healthcare
• unknown of how good the ACA healthcare will be: my current employer plan is A++++ and lots of fear around this plus partner has a chronic condition
• general unknown around future market performance (i mean who doesn't have anxiety about that)
• lifestyle inflation: $80K expenses was in the world where we aren't traveling a ton or having travel partially subsidized through work benefits; while i am good to travel cheap, i have also been spoiled through work and whatnot and can't suffer non biz class flights for international trips anymore ha. Also, i want a new car ($50K) and we have plans to do a one-time reno of our future primary residence ($800-1M depending on what i'm hearing from my friends!). basically the thinking that if i keep working, that 4M can easily double and then we're FAT.
• other things i can't think of right now (though let me know what is on your mind, OMYs!)

The irony is i know if i gave myself a weekend to sit down to research and model this out, I will know my shit and have a more solid plan (at least for the parts that can be known - like tax strategies or ACA). Yet that seems like not a lot of fun and it's much easier to just keep working away until the NW# gets so huge that it's like, well now you're just crazy for not retiring.

I asked the other day what people were targeting for their FI # (e.g., a 4% rate or other?) and some are even aiming for 1%! that just seems crazy.

curious how others in a similar boat as me are feeling and for those that managed to get through it, what you did :)