Stop working alone and start working together. Never allow silos to occur, because silos or hero developers are the symptoms of dysfunctional organizations. Sit together, closely. Define team standards together. Work in pairs and mobs; review together. Let the responsibility be shared in the team.
Organize code retreats, randoris and coding dojos regularly in your team. Spend 30 mins of each working day for just practicing.
Let the knowledge flow among people. Learn together. I’ve been organizing Brown Bag / Lunch & Learn sessions since 2010 every week in the teams I worked in. I heard twice, at different times, from my colleagues, “joining sessions every Wednesday allows me to improve myself and that motivates me a lot”.
Collect and deliver feedback. To gather collective feedback, you can organize Grand Retrospectives as I have done for years. By the way, Grand Retrospective is a new type of retrospective for digging into problems, with more than 20 people.
You are not children. Companies are not your parents. We have to own your career and invest in yourself. If investing means spending time and money, then do it for yourself.