There are a number of advantages, though only you can decide how important they are to you. These include (but are not limited to!):
- You are able to spend time outside the UK without worrying about losing you right to live in the UK.
Children born outside the UK can be automatically British citizens (by descent).
You can live and work in other EU/EEA countries (as things stand now).
Visa-free access to other countries is considerably better with a British passport than with an Indian passport (again, as things stand now).
You are able to claim consular assistance when abroad from the British authorities (in certain circumstances).
You are not worried about future changes in the immigration/nationality laws; in particular it seems likely that the requirements for obtaining British citizenship will become more onerous, not less — and changes are being mooted that are likely to take effect towards the end of next year — and that the pathway to permanent immigration status will become more convoluted (although that might not affect people that already have it).
You can pass through the British/EU/EEA/Swiss gate at ports of entry (a trivial advantage, 'tis true, especially these days when the EU queues are often slower than they used to be and the "other" queues are often faster).
Also, and in some ways most significantly, if you see your future in the UK, it seems to me to make sense to be a British citizen if you can.
The chief disadvantage seems to me to be that you will lose your Indian citizenship, although you can, I think, claim "overseas citizenship": you will need to look at the practical ramifications of that, and of course at the emotional ones as well.
Good luck with the decision-making!