Because Swiss scientists and businesses want to collaborate and trade with European partner networks of science and industries. One of the EU main principles i

Because Swiss scientists and businesses want to collaborate and trade with European partner networks of science and industries. One of the EU main principles is collaboration and win-win. It is not zero sum. Example: The Netherlands is wealthy and a net contributor, but would be poorer off from not being in the EU. Also, be aware that your question easily leads to a follow-up question: "Why don't we fund our own research and innovation?" => "Why do we fund research and innovation?"