Even with the features from the Player's Handbook, which are significantly weaker than what we have in BG3, Rangers are pretty strong all the way up to level 5. It's from level 6 onwards they start to fall apart since they scale so weirdly.
On a more specific note for BG3, I think there needs to be some rebalance of the natural explorer and favored enemy mechanics. For one, maybe not have even more bonus skills here? Rangers are a 3 skill class normally. In BG3 they are now a 4 skill class at the minimum, which the option to pick up another from Urban Tracker. Except it is more like getting 2 skills, since they use Sleight of Hand for both Sleight of Hand and Thieves' Tools. So Rangers are now a 4-6 proficiency class. Rogues have 4 skills and Thieves Tools normally, but actually have to spend a proficiency on Slight of Hand for Thieves' Tools in BG3, so they're down a skill.
Then you have the options like Keeper of the Veil and Find Familiar on ritual... like, what? A free Protection from Evil and Good every long rest in a Mind Flayer story is a significant boon, as is getting a familiar for free. These abilities are very powerful as far as first level features go and arguably makes Rangers too strong compared to Rogues and Fighters for our current levels.
I think Favored Enemy and Natural Explorer should probably have been implemented more akin to their optional variants in Tasha's Cauldron of Everything.
Deft Explorer
1st-level ranger feature, which replaces the Natural Explorer feature
You are an unsurpassed explorer and survivor, both in the wilderness and in dealing with others on your travels. You gain the Canny benefit below, and you gain an additional benefit below when you reach 6th level and 10th level in this class.
Canny (1st Level)
Choose one of your skill proficiencies. Your proficiency bonus is doubled for any ability check you make that uses the chosen skill.
You can also speak, read, and write two additional languages of your choice.
Roving (6th Level)
Your walking speed increases by 5, and you gain a climbing speed and a swimming speed equal to your walking speed.
Tireless (10th Level)
As an action, you can give yourself a number of temporary hit points equal to 1d8 + your Wisdom modifier (minimum of 1 temporary hit point). You can use this action a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.
In addition, whenever you finish a short rest, your exhaustion level, if any, is decreased by 1.
Favored Foe
1st-level ranger feature, which replaces the Favored Enemy feature and works with the Foe Slayer feature
When you hit a creature with an attack roll, you can call on your mystical bond with nature to mark the target as your favored enemy for 1 minute or until you lose your concentration (as if you were concentrating on a spell).
The first time on each of your turns that you hit the favored enemy and deal damage to it, including when you mark it, you can increase that damage by 1d4.
You can use this feature to mark a favored enemy a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.
This feature’s extra damage increases when you reach certain levels in this class: to 1d6 at 6th level and to 1d8 at 14th level.
