Generally, decentralized applications are lighter in weight
Do you honestly believe that BTC is lighter compared to ECB SEPA payments (Target2 ledger)?
BTC has to broadcast the transaction to every node, while ECB uses a single centralized computer to process the transaction.
We don't use BTC because it's lighter or cheaper. Revolut offers SEPA instant payments for €0, while BTC is way more expensive and slower:
https://mempool.space/I am not talking about BTC, which was a decentralized protocol that had its initial infrastructure built in
2008-2009. There's no point talking about Bitcoin as a modern decentralized application and at that, it is not even a decentralized application, it is an entire blockchain, built on an infrastructure that is not relevant to what we are talking about, being a forum application with more decentralization than what is current.
So to answer your question, no, I do not believe that BTC is lighter than other solutions because I am already aware that there are many more solutions that are much more efficient.
Payments was never a topic here. Using technology similar to that of Bitcoin to decentralize Bitcointalk was never a discussion here until you introduced it. Why people are thinking that we need to use technology similar to Bitcoin to power a decentralized version of this forum is beyond me, as the two are not even closely similar in their core use cases.