Theoretical Refinance Question

Can someone tell me what I’m missing here. I’m conservative/low risk by nature so the following will make more sense.
I have 24 years and 89k left on my mortgage. 4.5% interest. Monthly payment of 550 not including tax and insurance. value of conservatively 200k. 250k+ in current market.
I’m 32. Income of 130k and expenses about 3k/month. Saving/investing the rest.
I’ve been hesitant to refinance because the mortgage is so small and I like the freedom of knowing I don’t have to wait 3-4 years to recoup my costs if I decided to sell when a good opportunity came. Credit is 790-800.

I’ve been toying with the idea of refinancing and pulling out equity and putting it into a high dividend etf 7-8% yield (SDIV, etc)
If I pull out 50k in equity the dividend would cover my refinance cost after slightly over a year when accounting for capital gains.
If I pull out 80k I could essentially make my mortgage payment each year after, off of dividend yields.

This seems too easy. I know I’ve skipped some math. But this would essentially let my equity pay my mortgage.

I know there are better investments if I wanted to just put it into the overall market. But I invest my income already so just looking to put my equity to work. What am I missing?