Is it really this easy?

I have been following the tenets of this and similar subreddits for the past 6 years intentionally and for a little while before that unintentionally. I checked my numbers. I could stop working right now and have about $27k more in net income than I spent last year. Can I really do this?

My numbers:

Age: 57. No children. I do have a girlfriend of child-bearing age but she claims to not want kids.

Spent last year (2025): $78k (take home pay + tax returns - after pay money invested - difference in 12/31/2025-12/31/2024 checking account)

Amount invested: $2.1M (80% pre-tax (401(k), 457(b)), 20% post-tax (Roth, Brokerage, Savings/CD) Note I do not count checking balance, or physical assets (cars, etc.) in any calculation

Debt: 0, home owned outright

Income: union job paying between $200-250k (with OT). I have enough time built up that I could draw my salary ($160k) for about 1 1/2 years without working before officially retiring. In the 1 1/2 years of burning time I would stop investing and just live off of the base salary.

Medical: I pay 20% now through employer and will continue to do so after retirement. About $3k/yr

Pension: if I stop working now my pension will be about $36k/yr. Pension will not grow with inflation

SS: if I stop working now, SS will pay about $60k/yr adjusting for inflation

Potential retirement income:

I will subtract the SS amount ($60k) from my nest egg for 11.5 years, leaving $1.41M. 4% SWR of that is $56.4k. Adding the $60k from SS = $116.4k. I will only consider half my pension amount, since it will not increase by inflation. By increasing the amount used from the pension by inflation should give me a steady $18k for the next 40 years. That totals $134.4k.

I will pay federal tax on about 80% of the SWR/SS replacement, and on the full amount of the pension which comes out to about $19k.

I will pay state (NY) tax on about 80% of the SWR/SS replacement, and nothing on pension, which comes out to about $5k.

That leaves me about $110.4 k. I will subtract the $3k medical from that for $107.4k. If we assume that the $78k spent last year increases to about $80k with inflation that still leaves me with about a $27k surplus. Note that I would want at least that amount for things like home improvement or vehicle purchase, neither of which I did last year (I am spending about $20k on some necessary home improvements this year). Also note that although I have a good salary, it is union contract based and once I retire I would be not qualified for any high earning jobs so I have to be sure.

My tax situation should improve once my SS replacement is replaced by actual SS (only taxing 85%) and as I actually spend more of the pension instead of paying taxes on the 50% that I am not spending. I will have to pay taxes on my brokerage gains and savings interest, but I do that now so am not considering that as an additional expense.

What am I missing? Is it really this simple?