Rather than run monolithic Jenkins with a kagillion jobs in it that will easily bog down, you could consider running distributed Jenkins in which each team, or even each microservice, gets its own Jenkins Cluster with a small number of slaves and a small number of jobs. See my earlier post in this thread where I posted a YouTube video of the method I use for doing this using a CloudFormation template.

Also, when you say that your developers don't understand groovy, you could teach them how to ding make targets inside of their docker containers. That's the pattern we use at DoorDash... very minimal Jenkins scripting which exists to ding make targets inside Docker images.