In my opinion, bitcoin transactions are very slow, because they take around 10 minutes
Bitcoin transactions are happening almost instantly, but the 10 minutes that you were referring to is for the confirmation time
[or rather the average time between each block]... Depending on their fees and the network load, it might take you longer before you get the first confirmation.
Can bitcoin transactions be accelerated in the future?
Regarding its speed, it can happen temporarily when there's a huge inflow of miners or rather hash rates, but because of the difficulty adjustments
[every 2016 blocks (roughly 2 weeks)], it wouldn't last very long.
So theoretically bitcoin transactions can't be accelerated any more? When compared to altcoins that can be instant like doge or trx. Honestly, I don't know about the concept of pow, pos or anything else, I just hope that in the future bitcoin can be instant like altcoins.
I also read in the advertisement under the first forum post that bitcoin is still in beta status, does this mean that in the future bitcoin can be upgraded to be more sophisticated?