Short answer, things change, so adapt.
Changing to another (newer) KiCad version does take some time to get used to it’s new features.
The “interactive router” that Piotr mentioned was likely not present yet in an 8 year old KiCad version, and indeed you need the “modern toolset” to use the interactive router. A short survey of youtube video’s shows several of them on early 2014, and that was probably close to it’s introduction.
For me the Push & Shove mode of the interactive router was a very good reason to immediately drop the "legacy mode (Back then the KiCad canvases had names like “Cairo” or maybe “openGL”… Can’t even recall those names anymore 
The interactive Push & Shove router is a dream to work with. If you want to use it effectively though, you have to adapt your strategy in routing tracks. Push & Shove does what it’s name implies, it pushes tracks and vias aside during routing. As a result, I stopped caring where I first lay my tracks. You just put hem in approximately in the right place, (which saves time), and when you’re laying more tracks, they find better positions.
I can also vaguely recall undoing the “fix” of the last segment during routing, but now I don’t even know anymore why I wanted to do that. Maybe it was for a method that drew the track segments one by one? With the interactive router I often have 5 or more “live” segments before I fix them.
On Linux, the legacy mode has been dropped quite some time ( 2 years or so?) ago, and I can’t even select it anymore.
KiCad V6 is also ever getting closer. Recently I experimented a bit with it’s routing capabilities in KiCad-nightly V5.99 and the interactive router works noticeably better then it does in V5.1.x
Another aspect:
Do you use: Pcbnew / Edit / Cleanup Tracks & Via’s?
It can save some time to just ignore stubs, and then every half an hour or so do a cleanup of the pieces left over. If you don’t like the result of the cleanup, you can undo it with [Ctrl + z]. I also save my work before I do operations that could be questionable.