The advantages of IL for my mom have been

Daily checks: If she falls right after her morning check, she could still be on the floor for 23 hours, but it's something
Attached further levels of care: She doesn't need a lot of companionship, but once she has friends, she can keep them until she dies. She won't have to start over again
People like her: She is happy to volunteer as long as the chitchat is minimal. She has shelved a lot of books
Services on site: basic groceries, scheduled doctor appts, a podiatrist, PT and OT.

There is a huge difference in criteria for decision making if the senior is in their 60s vs 70s vs 80+, also taking into consideration physical ability to walk, exercise, drive, participate in any activities, and mental ability to handle their own affairs such as bills, operate a cell phone, handle appointments, use a reminder calendar, etc.

I know people in their mid 80s to even 90s who can do all of the above and people in their 60s or 70s who cannot. It's a very individual thing to figure out and it doesn't matter what everybody else thinks or is doing. And the obvious bottom line is finances and insurance coverage.

My mom is a super introvert and never really participated in activities at the independent living facility, or maybe very few. She'd go down for meals occasionally but I think she was pretty happy during covid when they brought the meals to their apartments instead.

The down side to independent living is no assistance for falls--no one checked on anyone even in the morning to make sure they woke up. My mom spent like 17 hours on the floor after a fall and was only found by accident when my brother stopped by to drop something off.

In the 90s my grandma lived at a different independent living place where they were checked on every morning, so I expected that basic level of service.

Fast forward multiple more falls and I started looking for an assisted living situation, got her moved and she continues to fall. In this AL, they are required to go to the dining room for meals unless they're sick or have doctors orders otherwise. Given my moms repeated falls and significant loss of vision, that seems kind of ridiculous.

She's had many more falls and about 3-4 weeks ago she had three falls in about 3 days and she's been in and out of the hospital and rehab facility ever since. Her most recent fall was at a doctors office and fractured her clavicle and a vertebra which required surgery. The incision isn't healing well and now she's back in the hospital for a blood clot.

I guess I went on a tangent, but all of this is to say it really depends on what your mom needs and wants, her overall health, whether you need/want someone to check in on her etc. If the IL place also has an AL place or rehab place, then that might be worth considering as a bonus so there's less moving around if she falls and injures herself. I would ask what services are included (like checking on them in the morning or tracking them down if they don't show up for a meal--making sure they're not on the floor etc.) These aren't things you think about until you've had to deal with them on the floor for 17 hours.

What can she afford and have you gone and actually seen the various places?

Op, you're overthinking this

Can she cook for herself? As seniors age, they can get to the point where they have difficulty doing the tasks associated with meal making - and sometimes they can become malnourished or dehydrated. I think this is more for folks with dementia, but physical decline can limit a senior's ability to care for themselves in this way. Also, even though she is introverted she might appreciate the meal time company.

That said, it depends on how big the budget is and how capable your mom is.

How does an elderly person decide which is the best setting for them?

My mom is pretty introverted and wouldn’t participate in planned activities. Really the only benefit to independent living is the meals. Is it worth it?