Why are the SIPC and FDIC limits not increasing with inflation?

"Why" questions like this are hard or impossible to answer, but I would argue that there is much more practicality in adjusting Social Security benefits and other items like IRA maximums, since those limits are continually relevant. When is the last time you heard about a bank or brokerage failure that triggered an FDIC or SIPC payout? And how many people do you think have enough in their bank accounts to even be concerned with the limit? It happens so rarely and is so high that the specific limit is irrelevant to the vast majority of citizens.

It's also easy to get around by opening multiple bank/brokerage accounts.

So perhaps the answer is because that no one has proposed an amendment or new law to tie these limits to inflation, since it doesn't really affect anything practical. I have no idea what the administrative burden would be to do so, but it's probably not worth it in any case.

My guess is that the next time there is a bank failure and there is public outcry that the limit is too low, then someone will make it part of a bill. Whether it's tied to inflation then is anybody's guess.