I'm not saying Bitcoin is not secure or decentralized, if I came across that way in the post, it wasn't the intention. I'm saying Bitcoin is not even close to scalable. Transactions take way too long, and are too expensive for a globally adopted currency. It can't scale in real world adoption, unless you sacrifice security, or decentralization by using an alternate network, like El Salvador has attempted.
Expensive; yeah there's an issue of that. However, segwit, and Lightening offer somewhat solutions to the expense problem, and in the future we'll likely see additional steps taken to reduce the transaction fees. However, due to the nature of Bitcoin, fees will always be a part of the network, and I'd rather higher security, a decentralised system to a degree, and paying a fee than giving up those benefits. I mean, a lot of people are already getting fees associated with their cards, they just don't realise it. Especially, if you own a credit card.
This is the reality I see for Bitcoin currently, and I agree I'd also rather have security and decentralization. But if we don't have all 3, where will that take Bitcoin? Will it ever live up to the original dream of becoming a globally mass adopted currency? The idea of being able to send money globally, instantly, securely without intermediary for super low cost was amazing. But it's not living up to that. And if it can't live up to that, where will Bitcoin end up, what will it actually be used for besides investing, trading, mining? That can't last forever, to me, if it doesn't eventually reach a point of mass adoption, being used in daily trade, it will eventually all fall down.