I really don't think a good chunk will be left. Not only are housing and healthcare costs rising in most countries and seniors spend a huge amount on healthcare in their last couple of years, but senior-living facilities are increasingly becoming more expensive AND some seem to have deals where seniors sign over all their assets to these centers - it basically means richer seniors help pay for poor seniors by pooling it all together... but the downside is that literally nothing is left to be inherited.

People funding 30 years of retirement while also dealing with inflation is super tough. I would guess that the vast majority of Gen X, Y, Z and A will inherit nothing of substantial value... you can see seniors already working way past normal retirement age (ie, Amazon Distribution centers) because of rising costs.