Both the first two Zelda games can get pretty grindy at times. For the first one, it's because high-ticket items require you to chop up mobs for cash for 1-5 rupees at a time to buy, for example, a ring that costs 255. For the second, it's because that game has RPG mechanics.
Speaking of which, unpopular opinion:
Zelda 2 is the best Zelda. The game is the perfect blend of platforming and sword-fighting for its era, the latter of which requires both fast reflexes and reading tells from the opponent.
As you said, in most Zelda games, combat mostly revolves around walking up to an enemy and pressing the attack button. Very rarely will strategy deviate from that pattern, unless it's a boss, in which case, the use of the dungeon item will be used to get it into a weakened state. If you try playing Zelda 2 with this mind-set,
you will get your ass handed to you. Which, aside from being a side-scroller, is probably why most Zelda fans dislike it. It requires knowing that the shield is your most-useful ally, and properly applying it requires more skill than just facing the right direction or holding a button. You need to carefully watch your enemy's movements to know whether you should block high or low, or in the case of the Goriyas that throw boomerangs, behind you, and you need to think fast. New players who haven't learned that your shield is your most useful asset and how to read opponents like Goriyas and Iron Knuckles will inevitably be curb-stomped as early as the first dungeon, but the difficulty drops pretty fast once you master it.
And that's exactly why I love Zelda 2: because it's a game that can be skillfully mastered in a way the series hasn't replicated since. Sure, you can
memorize other Zelda games, since those are mostly puzzle-based, and that is in itself a form of mastery, but Zelda 2 is an action game first-and-foremost. Is it perfect? No. One of the bosses is literally just "Cast Reflect, squat in the corner, and wait for the boss to kill itself," and the fight against Dark Link is complete bullshit without abusing the corner exploit. There's a string of "Nintendo Power Moments" towards the end of the game where you have to find New Kasuto, get the Magic Key, then play the flute to get the sixth palace to appear. Also, The Grand Palace is
fucking enormous, filled with extremely hazardous enemies that are advisable to avoid than engage, and to top it all off, features plenty of red herring pathways that don't lead to the final encounter. But those are minor gripes in what I perceive to be an underrated gem of a game.