BTCPayServer vs. Bitpay or other for accepting bitcoin payments in online store
It's my highly subjective opinion, but if you're not a government organization, using a service provider like Bitpay is a terrible idea. Bitpay was known to create anti-privacy features, perform KYC, and even known to stop some payments from going to the recipient. Every time you use a payment processor who is the custodian for the funds you want to receive you're in danger of losing those funds. And on top of it, you pay for that.
BTCPay is feature-packed, not only for bitcoin (segwit addresses) but also for lightning network, connectivity to hardware wallets and much more. If you want to use any compliance suit on top, cool, but you don't have to. Also there are no fees for using an intermediary. You can create widgets and use it as a patreon page, webshop, or just monthly subscription. Setup is extremely easy and running it in a light version costs less than $10 per month.