The plant parent's collection is their identity project, which makes gifting into a small political act. They have already decided which plants live in their house, which ones they're propagating, and which ones they've written off entirely. Buying them a plant sounds logical until you realize you're essentially picking an outfit for someone whose wardrobe is their entire personality. The real chaos here is not the shopping. It is the assumption that more plants is always better.
Consumables are the safest play. Plant food and neem-based pest sprays run out regardless of how many plants they own, so there's no duplication risk. A soil moisture meter is the one tool most serious plant parents have not bought themselves yet, despite needing it constantly. If they're in propagation mode (they probably are), glass propagation vessels or small terracotta nursery pots are the kind of thing they'll use immediately and never mention they needed. These gifts read as "I paid attention" rather than "I googled what plant parents like."
The trap is the plant itself. People reason their way into it: they love plants, so a plant is thoughtful. Nahi yaar. They have already sourced the plants they want from the exact nurseries they trust. A random plant from a mall outlet or a third-party marketplace seller lands two ways: they already have it, or it arrives with pests and they have to quarantine it from the rest of their collection. Either way, you've created work, not joy.