This adds volume and convenience, but causes some new wiring problems, and can be expensive if you use several instruments on stage. If you play in a band with a drummer, a lot of your choices are made for you. You pretty much have to give up the idea of miking the guitar because of the stage and monitor volume, unless your band's PA can allow you to send only the pickup signal to the monitors and the mike and pickup both to the house. At extreme volumes you might even have to stuff your guitar with towels to lessen its resonance and feedback. If you want to be heard, you might as well do your homework and keep informed as to the best way amplify yourself.
New equipment comes out every year.
Ignoring the problem doesn't make it go away. Musicians who spend years learning to play their instruments often don't realize that it is of almost equal importance to learn to use the sound system when performance time comes. Choosing not to deal with the issue is still making a passive choice, and if you don't use your PA properly, it still makes a statement to the audience, just as you make a fashion statement when you dress sloppily. You might be playing great music or speaking deep truths, but if the mikes are feeding back and the tweeters are blown in your speakers the effect of the truth and music may not be felt. Another performer with a great sound system and less truth is likely to connect better with the same audience.