[usbseeker]

If you are the lead, call a meeting, explain the tech stack that will be used, explain that their performance will be judged based on meeting deadlines using said tech stack, summarize this meeting in an email to your leadership, in this email explain meeting deadlines depends on using the tried and true tech stack you chose. If they refuse or come up with some contrived reasons why your plan won't work, methodically and politically knock those reasons down, institute daily stand up meeting where they have to explain progress or blocking issues. If employee misses deadlines they go on probation and then get fired. If management does not support you, find a new job then give your notice.

[UK-AL]

If people got fired for missing deadlines in software development everyone would be fired.

[gtirloni]

Please tell us how that is helping retention at your company.

[duxup]

At some point at every company they pick a stack and go with it.