Listen my parents were born in pre independence India. My mum was the headteacher of a huge school. My dad was a University professor before he retired. They both speak, read and write English fluently (my father was a professor of English). How do they live? Like other retired people in other parts of the world. They have a pension. They have investments. They don’t have a mortgage. Not everyone in India is destitute and surviving on scraps. We have literally no idea what socioeconomic status the OP’s in laws had. She may have quite a good lifestyle in India but it may still be isolating and lonely. And scary to be living alone.
We don’t really send money home to our parents (DH’s parents were also both civil servants and are now retired and have comfortable lives in India). We do pay for their tickets to visit us. And I have sent money home for things I know my mum will not buy because she likes saving money.
A visitor visa is granted for X amount of time. So you can have a 10 year multiple entry visa (my parents do). On that they can remain in the UK for 180 days in one go. So very theoretically they can stay for 6 months, go to India for a week, and then come back for another 6 months. However Border Control would not look upon this kindly even though it is ENTIRELY legal. I still wouldn’t report my MIL for deportation though...Usually my parents and in laws visit every 18 months or so and stay for 6-10 weeks. We enjoy having them here despite as I said my MIL being a little batshit (and my mum can be quite a handful too). It’s wonderful for the grandkids and I thoroughly enjoy coming home to fresh food after a long day at work. I feel very spoiled when they are here.
My parents and in laws both have two kids in the UK. They don’t ever expect to live with us. They do expect to visit for longer periods as they get older. There is a lot of assumption here about what happens in ‘poor countries’ on this thread.
My parents on the whole have a FAR better quality of life in India than many people in the UK. They are not ultra wealthy, but they live in a big detached house with a garden, they have domestic staff etc. Government healthcare though is very poor and private healthcare is expensive. My dad fell very ill earlier this year and the total bill over 6 weeks was close to 10,000 GBP. Health insurance is quite minimal in India.
There is so much misinformation on this thread about so many things that it is staggering.