Next is kind of mediocre, really. It is way too easy. You reach level 2 at 250XP, was it?
...this is the silliest argument I've ever heard.
Yes, you get to level 2 at 250 XP (as opposed to 3.X 1000). But guess what? The progression wave is much steeper.
Level 5 is 6500 (versus 3.X 10K), but then Level 10 is 64K (versus 3.X 45K), Level 15 is 165K (versus 3.X 105K) and capstone at Level 20 is 355K (versus 3.X 190K). It encourages quick early levels because every class has a Archetype feature you get to choose at Level 2 or 3 that really defines the game for you. Playing the first three levels is like playing on training wheels, so skipping them for most campaign is totally fine and usually thematically justified, unless your characters are brand new teenagers first encountering anything at all.
In addition, I haven't played a campaign (3.5, Pathfinder, 5E, etc.) that actually tallied and kept track of every kill, action and RP scene that could generate XP and then divided them out accordingly in YEARS. Usually the rule of thumb is "every two or three sessions for levels 1-5, every five or so sessions for levels 6-10, every 10 or so sessions for levels higher, etc.). If a DM wants, they can take five sessions to move to Level 2 with that 250 XP limit.
None of that makes 5E "easy." The action economy can be used by monsyers just as easily as it is by humans, making any encounter - just like any D&D product - a matter of how much a challenge the DM wants it to be. Given 5E's stated guideline of not allowing players to buy magic items and its barriers to crafting anything more than a healing potion, players are often at the mercy of their DM's to do anything outside of their class skills or the PHB standard equipment.
Truth is, 5E is more class and build balanced than any other D&D product (including Pathfinder), which not only encourages more interesting builds but also more interesting chafacter's in general. Given each race, class, archetype and background all have different abilities, features and Proficiencies that work together, you can have a different experience playing the same class ten different characters in a row, making it all about how you PLAY the character instead of how you BUILD them.