I also tend to agree that a lot of the Ranger Spells are just not that good or impactful.
Cordon of Arrows is trash. Sure, it is non-concentration and lasts 8 hours, but that only makes it useful as setting a trap while you sleep, it is still going to be a spell slot burnt and it only hits 1 enemy with each bolt, unless they enter and then end their turn still within the 30 ft radius. So, you are potentially getting four 1d6 attacks, and if the enemy makes the save no damage. Best case gets you 2d6 damage on two targets.
Compare as a "trap" spell, Spike Growth. It does take concentration, but it makes every 5ft moved deal 2d4 damage. No save. And makes it difficult terrain. So, while the enemy might blow past your Cordon of arrows and at worse take 1d6 damage, if they charge through a spike growth from end to end, they are taking 80d4 damage.
Same spell slot.
OR Flame Arrows. I will never understand why people try to defend this by saying that someone else can take the arrows and use them. That is the worst excuse for this spell, especially since it is 3rd level. It becomes only mildly useful if you have two or three archer characters all standing beside each other, digging out the arrows. But if it is just the ranger? No better than Hunter's Mark.
And I want to be clear, there are some great Ranger Spells. Steel Wind Strike is good. Spike Growth is good. Pass Without a Trace is good. Healing Spirit was good (until they nerfed it into the floor), but the rangers have just as many trash spells. And that is a bad balance for them