Often, it's not. You shouldn't assume "your basics" or that everyone has at least average SS income or waited until FRA. That's definitely not the case.
You're making a big assumption that the people who have no other income/savings are making the average SS income and waited to age 66. These lower income people are more likely to have started taking SS benefits earlier, like 62 where the average income SS payment is closer to $1200, but for so many people, it's much less than that, maybe $500 to $800/mo, many even less due to lower incomes and years worked, and Medicare and supplemental/medication/out of pocket medical will suck up a lot of that. They can't afford $600/mo for an apartment. Although, I live in one of the lowest COLA as far as rent, and I haven't seen any apartments that low since pre-pandemic. Maybe there's some shack in a dangerous neighborhood for that. Plus you would still have moving costs, utilities, renters insurance, groceries, etc. And you really need a car in those areas to get around - it's not like the urban city with plenty of public transportation.
SS simply isn't enough for a lot of people to live on, and seniors get excluded from some benefits like Medicaid expansion, which would have been very helpful to some seniors that I know. And if they can get free internet, big deal, that's not going to make up the difference what they need.
Then there are people who didn't work enough years to even earn social security benefits, and didn't work enough to get free Medicare part A, struggling to get by, but don't qualify for Medicaid either due to the very low income and asset limits. So they have no income at all yet have total Medicare (plus out of pocket) costs over $1000/mo. I know some affected by that.
I'm not sure why a trip to Europe was even mentioned vs. taking a trip to any other country or any expensive trips across the US if you are just scraping by. How about suggesting no paid rides on any space shuttles, as well? Ridiculous.
There are so many people out there that simply do not have the resources that most of the people on this forum have and won't get nearly as much of a monthly SS benefit (if any) as various forum members here who made high incomes over a long career and waited until FRA or age 70 to take benefits while also having a huge stash.