There are multiple clients for each platform & the official ones aren't necessarily the best.
By default, it only creates a server-client tunnel w/o packet forwarding (routed instead of bridged isn't sufficient alone), unlike a consumer VPN client. The OpenVPN company (yes, it's commercial) does sell a personal VPN product.
Servers can specify various options but clients don't implement them. Getting DNS config changes applied requires hacks (like custom shell scripts in Linux).
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