This sounds like an issue with your WiFi. Properly configured, a modern 802.11ac (or better, 802.11ax) WiFi router should be much faster than the fastest 4G or even 5G speeds.
We have up to 1Gbps 4G speeds in the city centre. But I just got 68 Mbps on the iPhone indoors (via fast.com).
The wifi router is just the cheap one that the ISP gave us. When I went next to it just now, it reached 330Mbps (also on fast.com via the iPhone's wifi).
Why main complaint is the latency of the wifi when we are in a different part of the flat, ie through a wall. I suspect there might be some packet loss and then tcp adds a few round-trips to resend packages and the congestion control reduces the amount of data sent or something like that.
Yes, I get pretty similar indoor 4G speeds on my iPhone X here in the UK. And I also saw exactly 330 Mbps via WiFi to my 5G router. My MacBook is a little faster, 430 Mbps.
I have heard of these claims of 1Gbps+ massive MIMO LTE in Singapore, but is it really achievable in the real world or just a "theoretical" speed? There are impressive speed claims for 5G here in the UK, but 500 Mbps or so seems to be the real-world peak for most current devices.
When I connect my laptop via copper cable to our fibre modem, I get just shy of the Gigabit.
Only a few handsets can achieve the Gigabit LTE. I don't think any iPhone is amongst them. (It is after all predominately an American device. And what good would that capability do you in the US?)
The Gigabit LTE is useful in practice not so much for any sustained Gigabit speeds, but because it allows your phones to 'race to idle'. Most traffic is bursty, and higher peak speeds mean your phone transmits for a smaller proportion of time. Leaving more time for other phones on the network, and perhaps helping with battery conservation?
