How Many Clients Could Not Send to Bech32 Addresses? For my client, I have set up a custom BTC payment solution using BTCPay Server.  The wallets I have configured in BTCPay Server produce only bech32 (bc1xxx) addresses for payments (cheapest transaction fees).
My client (who ordered the solution) has asked me how many of his customers would be unable to send a payment to a bech32 address?
His concern is that his clients will be unable to pay their invoices in BTC because their wallets will be unable to send payments to the bech32 addresses.
As I can see it, I can go back to my client with one of the following two answers:

Nearly all (??%) of wallets can send to bech32 including all\most commercial wallet providers so you don't need to worry, or
This is a problem and instead of bech32 addresses I need to set up a payment wallet that supports legacy addresses (either 1xxx or 3xxx).

Could someone please tell me whether I can reassure him that the solution is fine as is, or whether I need to add legacy address support into it?
As an answer didn't appear to be forthcoming, I did my own research in order to address this question.
Based on the information provided by the Bitcoin Wiki on Bech32 adoption, I surmised the following information.

All mainstream software wallets support sending to Bech32.
All mainstream hardware wallets support sending to Bech32 (either directly or via Electrum).
All major web wallets support sending to Bech32.
Most exchanges support sending to Bech32 (although notably Bitrex and LBC don't).

Note that I have specified sending because a lot of these do not support receiving funds via a Bech32 address as of yet.  However, for my particular requirement that is unimportant as it is about sending only.
With the above facts confirmed, the answer I actually gave to my client was:
Nearly all wallets can send to bech32 including most commercial wallet providers so you don't need to worry.
When he asked what percentage, I was unable to answer it.  I would need to know what percentage of daily volume went through the exchanges that didn't support Bech32.  However, given then pretty much every wallet does support it I felt that this was less relevant.