I agree with a lot of the complaints here.
- The extra damage added by the Burning Status and damage from surfaces are extra concentration checks which were not intended for the 5e rules. This makes it far easier to lose concentration, because any roll under 10 is a failure even if you took only 1 point of damage.
- Going prone should NOT lose concentration.
- Additionally, most spells/conditions which require saving throws need to be made at the END of a turn, not the start.
- Higher level, more powerful spells do not solve the problem of Concentration checks being far too easy to fail.
Yes, decent Con + proficiency in Con saves means that with some levels in you, you won't fail any concentration checks unless things are hitting you for big damage (like 30+ damage hits). Throw in warcaster feat for added goodness.
Any total under 10 is a failure for any Concentration check even with low damage. Max proficiency is +6 at level 17, Max Constitution is +5, for a total of +11. There's plenty of space to fail CON checks before you can get bonuses that high.