Because it costs so much electricity, several countries have imposed restriction on mining activity?
Mining of Bitcoin needs electricity and some countries like China first made restrictions in the electricity field that we only use enough electricity and not more because it consumes a lot of electricity as in this way it takes huge costs.
However China is also known by its solar energy system so they are not using that electricity in order to provide for mining but they did not handle that and failed. Many other countries are taking benefit from it and boosted their economies.