Air carrier Captain reported MMSD uses Tower frequency for both clearance delivery and local control; resulted in miscommunication; frequency jamming; and distractions on takeoff.

Narrative

MMSD Air Traffic Control Tower combines their Local Control and Clearance Delivery on the same frequency. I believe this is a dangerous practice. During our preflight; we contacted Ground Control to request our clearance. We were told to contact Tower for that. While monitoring ground frequency; we heard several other flights request their clearance and then told to go to Tower frequency. When we went to tower; the controller was clearing aircraft for takeoff and landing while simultaneously issuing clearances. Tower was spending more time reading clearances than controlling. Because of the language barrier; several aircraft had to have their clearance read back several times thereby clogging up (jamming) the Tower frequency. During our takeoff; just as we started to apply takeoff power; another aircraft started to read-back their ATC clearance. Because of the timing of this; we were unable to communicate with the Tower. And; the Tower would not have been able to communicate with us on the frequency. If we needed to reject or if the Tower needed to notify us to reject; there was no way to do that because the radio was jammed. Additionally; the distraction caused by the other aircraft jamming the frequency made it very difficult for me to concentrate on my takeoff procedure duties. My First Officer; who was the Pilot Flying; also complained that it was hard to stay focused during the takeoff; rotation and gear up calls. This is the second time this scenario has happened to me at MMSD and this is the second time I've written a report over this issue. Tower frequency is being used as a Clearance Delivery frequency. Tower frequency needs to be used exclusively for controlling aircraft. Clearances should be requested and received on a different frequency. Either on Ground Control frequency or a dedicated CD frequency.