Stating the obvious but it's not that BItcon can't be divided up, what I'm saying is overall supply will decline due to deaths and loss, more significantly than we think. I wouldn't think its crazy to say we might lose 1-3% in this way annually, that figure is plucked from my butt but still I'm betting it's significant.
My point is this gives Bitcoin a natural price increase all other factors equal.
The real problem with the coins burnt/lost is the uncertainty of whether the coins lost are really lost or just temporarily inactive.
Imagine what happens when 10,50,100 years from now there are only ~
BTC100k bitcoins in circulation (not a problem as it can be infinitely divided), and then you manage to recover the priv key to the wallet (say your deceased grandpa's) containing
BTC50k, which everyone considered "lost coins".
The very first moment you would make any withdrawal from that wallet, you will cause a massive panic and crash the market.
I'm not that much worried about the lost coins (due to death etc), I'm sure there will be a lot of solutions in the near future. But I'm slightly concerned about ideas such as Proof-of-Burn used in OpenBazaar:
https://blog.openbazaar.org/proof-of-burn-and-reputation-pledges/more like it would be a minor news blurb, "oldest wallet in use is no longer xxxx it is now yyyy". Kind of like when a 120 year old person celebrates a birthday these days. You click on the article, say, "hmm." and then make a stupid tweet.