Should I amplify the antenna signal?

Question

WiFi

Good day, dear Toasts!
I have two access points, which are separated by about 1 km. Two directional antennas are used on both sides. On my side, the antenna is weak (unfortunately I can’t tell the company and model, but the antenna looks like a tile, I’m not at all sure that it is with gain), on the other hand, the antenna is more powerful, definitely with gain, but again I don’t have data (.
Not so long ago, problems with the network began, the transmission speed dropped sharply, by 80%, they removed it, unscrewed the cable (which is from the antenna to the access point, 9m long) and found some water there, they thought that this was the reason, they sealed everything and hung it back . And here again the speed fell this time there was no water, the sealant was the same. The antenna was moved to another place, under the roof, but now it’s bad luck, trees and birch trees grow on the signal path, but the signal is good (14dbl), the reception speed has increased, but not to the maximum, somewhere 85-90% of the original. But the speed of return has risen slightly and barely up to 40% of the original. Is it worth looking for a more powerful antenna or is the problem in your hands and is it worth trying to point the antenna more accurately for a better "catch"?