Beethoven major income is teaching and music score sheet, unlike Hayden in concert. He failed very much in the concert music. Still remember the concert where no 5 the fate symphony was doomed.

His sonata was never played (or may be once) in the first 100 years in public. It was meant to be read and played to the score.

If not mistaken his last act is to rewrite his quartet to 4 hand as this is very popular music at home. There is no mp3 and we do not have 4 person at home unlike Schubert.

But the difference is circulation is still a bit limited. Hence some can still survive. Imagine today if Beethoven is here, he would not be struggle and worry about income in his dying bed. (He would not be starved to death or without a drink. The newly formed London symphony society heard about his worry and sent in money for his tenth and later wine. But even he is on ...)

Beethoven was one of the first pianists to survive without a major aristocratic sponsor, so that was an accomplishment for his day even considering his stature. Not only that he was able to accumulate assets, like shares in a bank, that put him in middle class.

However he did have some unfortunate twists - war caused him to lose a stipend income, promised to him so that he doesn't take up a well paid position for Napoleon's brother. Then of course a period of inactivity due to depression.

For the sonata... are you referring to the Hammerklavier? That was simply a monstrosity of a piece, but it was played in concert only a decade or two later by the virtuoso Liszt.

I agree though, the audience that Beethoven could reach today would well exceed what he could from 1800's Europe, even if most people today prefer pop.