You can easily set a constant drip to have EXACTLY the same amount of water change as a periodical large change but the constant drip is far better IMO for several reasons;
1) slow gradual water change is always less of a shock than a large sudden change in terms of temperature, pH, hardness, chlorine, chloramine, ammonia, nitrite etc. The new water coming in is very different from your tank water (otherwise, why water change?) and even the new water on different days is surprisingly different.
2) Temperature in winter alone is sufficient reason for constant drips especially as running coils of cold water pipe through a hot water system, solar pipe or warm fish room where water flow is slow enough to absorb heat is beneficial.
3) You will always get sudden unpredictable ammonia/nitrite spikes in your town water supply (as well as other chemical spikes dependent on water board). While a continual water change will guarantee you get each and every one of these bad water days, contrary to logic, you get far less then doing a large water change on a day when the water is bad. Should you get a high ammonia level (for example), your filter will cope much more easily with a slow feed over time than a large sudden spike. Unless you test for a wide range of chemicals just before each and every large water change, you will eventually get caught doing a large change on a bad water day. If you are only able to water change on your weekends then this is even more of a problem
4) Continual water change is much less effort in time and labour. Even if automated, large sudden water change systems are more problematic since they are more complex by nature.
5) Continual water change is in drips (milimeters per hour) which allows for low pressure taps, pipes and fittings. Much cheaper especially if you have multiple tanks/fishrooms. Pressure pipe/fittings which fail will lose a lot more water and do much more damage than a slow leak, especially if you are not home to notice for several hours.
6) As you have already mentioned, doing a gradual drip water change allows you to use chlorinated water safely..... ie even at chlorine levels where a large water change would be fatal, a slow gradual change would still be safe.
7) A gradual water drip is extremely easy to visually check all is working. Just make sure the drippers are above the water level so they cant clog and you can see drips.