I would argue that DnD5e is very lax with party composition, plenty of folks did just fine with an atypical or homogeneous team. I have seen a 4 paladins run or even solo runs go through just fine. Multiple classes fit the archetypes you described if shoehorning your party members into strict roles is your thing, so that leaves plenty of room for freedom of choice.
Unfortunately, if you don't have a frontline, then your squishies ALL become your frontline. Which I think we can all agree is bad. You can argue that a team of all wizards could account for this by all packing shield and other defensive/control spells, but then you are really cutting into their DPS and eating through their spell slots.
While I agree that there is a lot more freedom in building a party in 5e than there is in something like WoW. You still need some basic functions in order to be successful.
