DW is 6+ years older than I am, and we have similar work records toward SS. Mine will be higher if I take it at age 64 or later (I'm 61 now). But because of the age difference and SS work records, there was no advantage for DW to wait until age 70 to take it because my own record would be higher than 50% of her maximum.
When DW was laid off a few months prior to turning 65, she started SS. This was her preference. Along with my modest pension that I started at the same time, ACA was pretty much out of the question. It didn't matter anyway since I had access to an under-65 retiree medical plan (which required starting the pension) that, while not a Cadillac plan, had much better maximum cost scenarios than with ACA, even with the subsidies considered. Not having to play the ACA tax game was a plus as far as I was concerned.
For myself, I am left with the decision of when to start SS. I could wait until 70, but family age history is not my friend. Also, DW's SS will always be higher than 50% of whatever I end up with on SS, so no benefit for her by waiting. I am leaning toward doing the same as her, starting at near 65 and have Medicare premiums taken out of that payment.