Needless to say, the credibility and acceptability of Bitcoin is growing day by day; At the same time, its value has also increased. Bitcoin is now widely used as a medium of transaction as well as investment. Bitcoin transactions can be done very easily, securely and at low cost. But the big problem is that its market value is very volatile. So I think you should think long term about investing in Bitcoin.
I don't agree with your statement. I am not witnessing much growth after mid-2018. The growth in the user base and acceptability seems to have stagnated. Also, a number of stores that used to accept Bitcoin payments earlier are no longer doing that (such as Stripe and Steam). High transaction fee, as well as volatile exchange rates are to blame for this situation.