Inkscape é um editor SVG de código aberto. Deixarei a documentação tirá-la daqui:
The main use of the Simplify command (Ctrl+L) is reducing the number of nodes on a path while almost preserving its shape. This may be useful for paths created by the Pencil tool, since that tool sometimes creates more nodes than necessary.
Você também tem algum controle sobre o limite de simplificação:
The Simplify command is accelerated. This means that if you press Ctrl+L several times in quick succession…the threshold is increased on each call.