I have a hotspot running on a Mikrotik RB.
I needed to route all traffic through a VPN connection. I just added a new PPTP Client and checked Add Default route, and everything worked well.

For my own study and learning/curiosity I wish to understand why the VPN tutorials for Mikrotik always suggest the mangle rules be added and static DNS entry for google, as you can see on the following links
https://community.hide.me/tutorials/mik ... tp-vpn.59/
https://nordvpn.com/tutorials/mikrotik/pptp/

The idea is to have selective routing: only a subset of connections will go over vpn -> the marked ones.