The Netherlands has NaWas non-profit service that filters out DDOS attacks, in Q1’22 7,4 times per days with DDOS traffic up to 300Gbps. It’s a few man shop, costs of membership are low. From their FAQ
https://www.nbip.nl/en/nawas/faq/ :
The NaWas infrastructure is designed as an on-demand service. After detecting an attack, the traffic is routed via BGP to the NaWas hardware and then the mitigation process starts. All traffic is then rerouted and the own connections can thus manage with less capacity and thus remain cheaper.
To connect to the NaWas, a port must be available from one of the following parties: AMS-IX, NL-IX, LINX, NET-IX, Top-IX, M-IX, V-IX or one of these cloud interconnects DCSPine, Epsilon, Megaport.