Lightning Network is a beta and on-going process which needs a few more years for the widespread usage. As of now, there are far less nodes which made a part of the network as a centralized one. Last month I got to read a theory that over 8-10% of the nodes are in control of most of the funds which are going through lightning Network.
I know but the Lightning network has its very high potential for more widely usages in the very near future. When it becomes more widely accepted, its network will become more decentralized.
Segwit was another major improvement to scale bitcoin transactions by including more transactions in a block. But they are never really related to Lightning as they can scale a million number of transaction processing per second. Either we need more adoption towards bitcoin by not just using them as a store of value or considering them as a digital gold standard but rather using them for global payment services.
Segwit at its beginning was supported on very limited number of exchanges or platforms but nowadays, most of exchanges / platforms and wallets already support Segwit. So everything need time to fully matured and accepted.
The primary goal of a currency is to be used as a medium of exchanges in a more faster way. Bitcoin has the ability to work independently without the intervention of third party but scalability seems to be a major factor affecting its adoption. Similarly Schnorr Signatures are a groundbreaking addition to bitcoin to improve the scaling and privacy features being governed by sipa. There is a long way to go and we are just 10 years into bitcoin.
That is not what I agree with you. Bitcoin is a backbone of crypto and it made the world known about the blockchain technology and the ecosystem of cryptocurrency was born from Bitcoin's contributions.
But I don't think bitcoin will grow further as a main means of exchanges, that tends to be the responsibility of altcoins. Bitcoin, in contrast, will maintain its role as a digital Gold and serves its role somewhat similar to Gold.