Business savvy!! The vast majority of people that die won't get anywhere near the threshold for paying inheritance tax. As I posted earlier, in 2019 there were only 23k deaths out of 500k that resulted in IHT being paid. You also make it sound like the Government take the lot, they don't...
Remove one tax then you have to raise the money elsewhere. IHT only affects a small proportion (23k in 2019/20 out of about 500k deaths) so that could be changed but wouldn't be popular. There's already a section of society that moan about it despite the fact they are unlikely ever to pay it.