Eventually everything is an actual upgrade of Bitcoin, even Bitcoin itself.
Creating an exact copy of something and changing its name while decreasing its security is not an upgrade.
The Segwit implementation/upgrade and block size debate has split it in 2:
Wrong. Bitcoin has never split into anything. People have been creating poor copies of it for ages but they are not "splitting bitcoin".
Timestamp is a form of time dependency (time-stamped).
The network is "writable" only for a 10 min window after which it becomes immutable.
Wrong. That is not how Proof of Work works. There is no "10 min window" at all in PoW.
But Bitcoin isn't yet optimized for this purpose: High transaction time & fees, network congestions, no privacy, no other use cases (utility) for the network like ETH or EOS.
Bitcoin is as optimized as it gets and so far there hasn't been anything better in having faster cheaper transactions while remaining decentralized.
BTW creating tokens to scam people (ie. what ETH, ... do) is not called "utility". Smart contracts exist in bitcoin and if any more advanced contracts were needed and had any real world application they would have been added to bitcoin. There is also sidechains (eg RSK) and a ton of other things built on top of bitcoin (eg. Omni layer) with much more advanced smart contract capabilities.