Comparing speed of the Raspberry Pi 4B running from SSD Samsung 850 EVO versus microSD card Kingston class 4:
Raspbian - 40s. instead of 122s.
Chromium - 4s. instead of 26s.
Kodi - 6s. instead of 20s.

Question is if it is worth the price of the SSD drive and the SATA>USB adaptor. Depends on your RPI usage.

How to run Raspbian on Raspberry Pi 4B (and higher) from external SSD drive:

Boot Raspbian on Raspberry Pi 4
connect SSD drive to a USB 3.0 port and it should detect the drive (show dialog).
click raspberry menu, accessories, SD card copier
select to Copy from device /dev/mmcblk0 (SD card)
Copy to device /dev/sda (SSD drive)
tick "New partition UUIDs"
run the clonning
Open terminal: Ctrl+Alt+T
execute command:
It should show the partitions on the SD card and on the SSD drive.
it shown the root partition (part /) being named mmcblk0p7 , thus having number 7:
-mmcblk0p7 179:7 0 4,6G 0 part /
in the terminal execute following command (making sure mmc partition and the sda drive really exist per the previous lsblk command output):
sudo sed -i "s/mmcblk0p7/sda7/g" /boot/cmdline.txt
and then command: reboot
RPI4 should be rebooted and running from SSD (/boot partition still have to run from microSD card).
To return back to SD card, edit /boot/cmdline.txt and replace sda7 by mmcblk0p7.