I'm just gonna copy and paste the comment I wrote on reddit earlier this morning, specifically responding to someone asking why lots of people say not to replace original wood windows.
Because properly maintained and cared for with the addition of storm windows, original wood windows look better, last longer, and are just about as efficient as modern double paned windows. The key is properly maintained, and most people don't put the effort or money into that. As you have evidence of currently.
If your vinyl or aluminum window breaks, there's generally no fixing it. Wood windows you can rebuild. And the fancy doubled panes are great, up until the point when the seal breaks. And they do break. Plus the environment concerns around disposing of the modern windows.
Rebuilding, glazing, and painting wood windows are all diy-able. Some things are higher skill than others of course, but you can learn.
If your windows are too far gone, you can buy new wood windows, but they are expensive. You can also get windows that were pulled out of older homes, fix them up and install them. However, you need to commit to the maintenance or you're just pouring money down the drain.