I think it has a lot to do with work culture. Many tend to mimic what others are doing in order to not stick out.
At my previous job some were able to change that by consistently using "modern" features of Java. It inspired others to change and eventually we ended up with a good code base.
Be the one to start the change by implementing new features using good code. This will give others "permission" to do the same. Also try to give soft suggestions in code reviews or pair programming of simpler ways to do it (don't push too hard)
At my current job all of us were eager to try the latest features from the start, so we never had to convince new hires.
At my previous job some were able to change that by consistently using "modern" features of Java. It inspired others to change and eventually we ended up with a good code base.
Be the one to start the change by implementing new features using good code. This will give others "permission" to do the same. Also try to give soft suggestions in code reviews or pair programming of simpler ways to do it (don't push too hard)
At my current job all of us were eager to try the latest features from the start, so we never had to convince new hires.