[faeyanpiraat]

You mean that I can have 1btc in 1 piece, or have basically 0 usable btc if I have 1btc gained in like a 1000 small transactions over time?

So when I “spend” that fragmented 1 btc, it all gets eaten up by fees?

[Hjfrf]

There was a update on bitcoin last year ("taproot") to improve that issue.

Prior to that it was absolutely the case that multiple sender addresses caused multiple fees.

Not sure about other cryptocurrency.