That's like saying "We found that 4e played fine when everyone played a Leader". Sure, you can play that way. Your party is dysfunctional WRT the expected capabilities for a group of its level. Without a cleric in 5e you have drastically reduced survivability, and you could use any and all of the methods you list, but adding a cleric to that is still a quantum leap in resiliency.
We haven't found this to be the case. In fact, this is the first edition we've been able to play without a cleric. Even in 4E our group due to our play-style required a cleric. The warlord did not heal near as well on a consistent basis. None of the "Leaders" did. The cleric was the best healer in the core rulebooks. Maybe expansion changed this. Our foray into 4E almost always included a cleric. We tried the warlord. He just didn't work very well for healing. We play a vicious game.
In 5E we've found both the bard and druid are viable healers. The druid brings so much to the table he can often mitigate damage preventing the need for healing.
You still need a healer in 5E. That part I agree with. You now have the option of bard, druid, or cleric. The only cleric that is clearly the best is the Life cleric. One level of life cleric can turn the druid into an amazing healer. One level of life cleric turns goodberry into an amazing spell.
We were all surprised this is the first edition of D&D that we could play without a cleric healer. In 3E/Pathfinder channel energy was king at low levels. In 4E the cleric has better healing powers in the core book. In 5E the cleric is a relative equal to the druid or the bard.