Flaws of Bitcoin

In order to underline the ineffficiencies of the Bitcoin design, we need to look at the basics.Around the globe, everytime a transaction takes place it needs to be put on the blockchain at some point. But how do we know this transaction is valid? Someone needs to check it, and it needs to be reliable. As opposed to bank transactions, which are checked by a central authority, the Bitcoin introduces an original concept: a decentralized way to reliably confirm transactions

It's time to make a recap of the algorithm. Every 10 minutes, a new block of data consisting of transactions are added to the blockchain(it's a chain because it contains a link to the hash to the previous block). Before a block is added, to the string containing all the transactions is appended a number x, and then to the result is applied the SHA256 cryptographic algorithm, which transforms a message into a string containing 256 bits(only 0s and 1s). The "proof of work" is therefore guessing what the number x is so the hash begins with 30 or 35 zeroes. This likely takes billions of iterations, and this is done my multiple parties(miners).

Now that we've recapped how the algorithm works, it's time to outline why this is inefficient. First, every block has a maximum size of 2MB, which will result in a maximum amount of roughly 4.6 transactions per second. How is mass adoption going to happen when there are far more transactions happening in the world? As a comparison, Visa can support up to 24k transactions a second. Also, the mining process is inefficient in regards to the fact that the same hashes are calculated for the same number x by all the miners(the most efficient way would to be calculated only once)

Is it possible for some of the things stated above to be solved somehow? Don't get me wrong, I like the decentralization of Bitcoin and the concept as I am an investor myself, I just don't know how many of you are aware of the negative things.