It depends on your use of the car and it's electrics but only 2 years out of any battery sounds bad, Varta are normally a good make and EFB or EFB+ whilst possibly not as good as AGM aren't that bad. The battery gets the blame for many electrical and charging issues when the vast, vast (twice) majority of times it isn't the battery at fault, rather a problem with the car (part(s), component(s), system(s), programing) seen many times with VW - or and I'm not suggest this is the case this time, but other times, it's the use, abuse, neglect of the vehicle owner/driver(s). Varta is a reliable make, most are, VWŠkoda vehicles have been proven to be less so by all the different threads and posts on the various models of "battery problems". By all means fit a new battery for yourself and code it in (do this carefully to have correct data entry, loads and loads of examples of how on the various model forums here or I can post up info again here - but if you still have the car in 3 years time I expect you might have the same/similar issue (if not before). Good luck, let me know if you want battery 'coding' info (to confirm what you might already know, even more relevant if going AGM).