merge will have a big impact on gpu miners so after merge at least 95 percent of the gpu mining revenue will disappear so gpu mining will be unprofitable again unless some gpu mineable coin replace it which is unlikely to happen in the near future . Projects which choose to build on eth network they use eth becaue of the network security if i'm not mistaken so if after merge eth network can keep it's reliability then it will keep growing in the long term . i myself think that eth will dump 50% in a year because of the economical reasons even merge happens succesfully i don't think it will have big impact on the price