This is probably one of the more popular questions we get asked frequently.
Speed...... that is a big and complicated issue. There are many variables to think about when it comes to answering this question. The most obvious variable is signal strength (distance from tower). This is not the only thing to look at, but it is important. Generally speaking, the first thing that can/will affect speed is your signal strength. The farther away you are, the lower the signal level, the more work the router and other have to do to communicate which results in lower speeds.
Next we have to think about congestion. This is the single biggest problem when it comes to speeds. Think of the cellular tower like the water pipe that comes in to your house. it is connected to all of your water-needing devices (sink, shower, toilet, outdoor taps, dishwasher, laundry, etc). If you start using lots of these at once (take a shower, run a load of laundry.... and dishes, watering the lawn, and filling the swimming pool all at the same time), well.... you get the idea. Now take that concept an apply it to the cell tower. With more and more (almost everyone now) working and schooling (and video gaming, and movies, etc) from home now...... well..... there is "only so much water" that can flow though the "pipe" at one time. To further show this to be the case....... try running a speed test sometime between 2am and 3am and see what you get as compare to 2pm and 3pm....... its a HUGE difference and that is what is referred to as congestion. One last way to think of it is like the interstate highway.... it really does not matter what the speed limit is if there is a traffic jam or rush hour.
Next we can think about "bands" which is also important. Every tower (almost) broadcasts in multiple bands. Some only 2-3 and others as high as 5-6 bands. Think of each of those bands like the highways we just mentioned. Each "road" has a different amount of traffic on it. Some may be faster than others. Our routers (and probably yours too) are set by default to pick "what it thinks" is the best band/strength. In this case, a weaker band may be the stronger one. Sometimes it is best to "lock" on to each one and test it for a while to see how it performs for you.
The bottom line is.... we are unable to guarantee any particular speed to anyone. There are just too many variables. And sadly with the pandemic, it is only getting worse and worse.....