Where are VPN today now in 2020?
Cowbee is always watching and following closely towards VPN market, there are many VPN protocols and technology are implemented, namely, PPTP, L2TP, L2TP over IPSec, SSTP, ShadowSock, Microsoft SSTP, OpenVPN, EtherIP/IPsec etc.
In 2020, PPTP is slowing moving out from the major market as majority of mobile device vendor are removing the support of PPTP, typically iPhone IOS 13.7 and newer. L2TP/IPSec protocol seems dominate all the mobile devices including PC/MAC/Linux/Android/iPhone. From performance wise, it is widely expected with little speed overhead 10-20% delay, whilst OpenVPN protocol is very slow performance (50-60% overhead), ShadowSock/MS-SSTP are not that slow performance but complicate to support and use for many mobile devices.
In future, VPN technology is an ever changing technology as user requirements is evolving from time to time, more mobility + more security are emerging and heading for optimizing network experience.