It is growing now in proportion to bitcoin. I have not seen the net growth of ETH for a long time. If bitcoin falls, then it is generated at ETH. If it grows, then it also drops on it. Of course, if you believe that Bitcoin will continue to grow, it is worth investing in ETH.
If bitcoin continues to grow, it should be better to wait to get cheaper Ethereum. However, It is really challenging task for bitcoin because it has stucked in its re-consolidation phase, from $9000 to $12000. I don't believe bitcoin will break its current very strong resistance around $14000. Maybe when halving comes closer, it will break that range.