A guitar amp is an effects box that happens to also amplify. they're not generic sound reproduction systems!!!, they've got overdrive without clipping, and implement various forms of EQ (including the speaker acoustics!), limiting, distortion and tremolo.
You can get digital guitar pedals that emulate a massive selection of "classic" guitar amps so you don't have to deal with the real thing (and its unreliability, fragiility and expensive replacement valve purchases!)