I usually go straight to the full language. It's pretty hard to find the point when to switch from low code to something else when there is time pressure.
Same with bash vs python. People say you should switch from bash once you have more than 100 lines or so. But at this point you already have some complexity in bash which makes the switch to python non trivial. So you usually end up patching the bash script in small increments as needed. It gets messier and messier but nobody wants to/can spend the effort for a full conversion
Better to immediately switch to Python (or anything else) once you have any non-trivial control flow in your bash script. Loops, non-trivial conditionals, and argument parsing are all easier in Python. Bash is for simple scripts that just chain commands.
Unless you're a regular python user who has already paid the high cost of installing learning to use the whole mess of tools, the break even point exists. There are times when I do the 100+ lines of shell to avoid python. How often do python apps just stop working on me for no apparent reason? (Yesterday I tried to launch puddletag and had to nuke it and reinstall). But for me the big thing is that using "curl | jq | awk" is easy, fast and terse. If I can get away with that I'll choose it every time.
If you're using simple pipes with little control flow, bash is a great choice. Once you need something more complex, you're better off using something else. Not necessarily Python (Ruby and JS work well as replacements, too), but that would be my first choice.
For most simple scripts, Python's standard library is more than enough. File operations, JSON manipulation, HTTP requests and argument parsing are all available without external packages.
Regarding Python apps, have you tried using pipx to install them? That would eliminate most dependency problems, which usually arise from sharing the same environment (potentially including conflicting dependencies) across different apps.
Same with bash vs python. People say you should switch from bash once you have more than 100 lines or so. But at this point you already have some complexity in bash which makes the switch to python non trivial. So you usually end up patching the bash script in small increments as needed. It gets messier and messier but nobody wants to/can spend the effort for a full conversion