Why haven't IRA limits kept up with inflation? original $1500 limit in 1974= $10,132.45 today

The IRA was created in 1974 with an annual limit of $1500, which adjusted for inflation is equivalent to $10,132.45 today, however the current IRA limit is $7500. That was for all ages too. Even the catch up contribution limit boost today is at $8600. still below the original dollar value. Shouldn't we have at least the same contribution limit as our grandparents did? I mean I guess if you want to say the original dollar amount was arbitrary and we shouldn't base today's limits on that, but it s