This is exactly correct. For most folks, whatever sound the integrated card makes is enough. Until you are producing music, that is - and then, the external has easy connections for the equipment.
Thanks for the recommendation. I've been needing better audio quality from my machine than it can produce, but it's actually pretty hard to figure out how to accomplish that if you don't already know.
Been through three different external audio devices, and they've all sucked. I'll try yours.
I have MOTU, Universal Audio and Audient which are all good. But they are general aimed at musicians/producers etc. I would also recommend RME if you use a Mac or just the ASIO drivers on Windows.
The drivers are really important, and often audio interfaces aimed at professionals will use a driver that a DAW can utilise with control over latency. macOS users tend not to need to worry about this so much because as long as they are good it works, and on DAWS on Windows I use ASIO because MME, WASPI and WDM have had poor behaviour and/or latency in the past. But for general music listening those other driver types should be ok if the manufacturer supports them well - but this is where the problem might be.
I am guessing it might be the driver that sucks in your experience?
Have you tried S/PDIF output to an external convertor?
There are many other respectful audio interface makers, not only Focusrite Scarlett line: MOTU, Arturia, SSL, M-Audio, Native Instruments, Behringer, Steinberg, Presonus…
I think in practice all of them are good enough but if you’re into numbers, dB, Hz, and measurements, check out Julian Krause audio interface reviews on YouTube.
I have an external soundcard but don't use it as the DAC in my laptop is now good enough that I don't hear the difference. Either the laptops have better chips or my ears got worse
And for connectivity. Even for the small band I was in, doing "home" recording we had ~10 microphones and 2-3 direct line-ins set up recording simultaneously trough an external interface and out to 5 headphones or two different sets of speakers.