Before we could just buy and own a property there, work, use the health care system, travel in and out. But now I is not that easy
Both Spain and Portugal have visa restrictions now that mean you can live there full time and if you want to apply to get nationality then you have to move all you pensions and pay all your taxes there and not in the UK.
To qualify to live there all year you also have to buy a property that needs renovation and is expensive. You also have to have a 'passive income' which is quite a lot, and since I am not retired I can't use pensions for this. So it's not as easy as before Brexit.