It depends on the hardware you have.
LG's are among the best music devices on the smartphone market and compete with mid tier daps, yes.
But that only applies to the dac and its abilities, as a all-in-one solution, and excludes the amplification capabilities of mid tier daps and higher.
Maybe you're used to the lower accurate sound reproduction of your pc when it comes to fidelity.
Of course, that isn't a bad thing, but do exist.
Without knowing your hardware, it's hard to figure that out.
Even a simple device as the FiiO BTR5 could be an improvement.
Advantage of this little device is you'd be able to use it via usb on your pc and coupled via bluetooth with your smartphone.
This is a cheap step up, i think.
Imo, it's better to buy this one before heading to the LG phone in regard of usability when you stick with your current earphones/ headphones.
Sure, you can get better sound quality/ amplification all the way, but this will charge at least round about 4 times the price of the Btr5, imo.
In the end, it's up to your how much steps you climb the ladder.