Mine are fairly small, single-person projects. I’m not part of a team. The stakes are small. I’m sure it's much different on larger team projects

The project that prompted the question is a single-person project...

Historically, my company has relied on Online Travel Agents (OTAs) - Airbnb, Booking.com, etc - for finding guests for our Furnished Holiday Lets. It was always part of the plan to have our own booking platform but it was on the list of things to do 'one day'. And then the Pesky Pandemic arrived and the OTAs basically cancelled all booking and wouldn't take new ones. Although people couldn't stay with us for leisure, there were plenty of valid reasons for people staying. So, suddenly the booking platform became very, very urgent.

I created a fully functional booking platform from the ground up in a little over a week. On the backend there is a basic CMS to allow other team members to upload and change pictures and text.

Last year when I created the booking platform, I knew of the Monastery but hadn't created an account and knew absolutely nothing about templating or separating logic from display or anything like that. So the whole system is very badly written but it does what it needed to do. Now, whilst I am quite proud of my achievement, I want to refactor the site to use Template along with use strict; and use *::*; instead of require */*.pl; and all sorts of other good practices that I have learnt in the Monastery. The reasons for refactoring are so that we can make incremental A-B testing changes much easier and so that someone else can take over the display and design at some time in the future; not to mention making maintenance easier!

So, like you Radiola, this is a small, single person project in many ways. I am not part of a team although the stakes are probably a bit higher!
Having the wisdom and support of the Monastery to call on makes the prospect of refactoring bearable - otherwise I would approach it as throwing away everything we have except the DB design and starting again from scratch...something that would forever remain on the 'one day' list.