What the Reaper actually does
The Reaper is a mechanic that follows your character and cuts your max HP in half, according to gamestratwiki. That sounds like a downside, but a smaller HP pool means enemies kill you faster, which shortens the time between deaths and lets you loop through the game's core revive-for-damage bonus more often.
What the Reaper Follow gamepass adds
Reaper Follow keeps the Reaper permanently attached to your character instead of you walking back to it, per gamestratwiki, which lists the benefit as faster revives, faster farming, and better long-term progression. The site frames it as a quality-of-life purchase rather than a stat boost — it saves time, it doesn't make your character stronger by itself. No source checked for this page publishes a confirmed Robux price, so treat any specific price you see quoted elsewhere as unverified.
A free shortcut some players report
A viewer comment on ItzVexo's guide video describes a portal button in the top right of the screen that teleports you to the Reaper without walking. That's a single unverified player report, not confirmed by any guide site checked for this page, but it's worth checking for in-game before spending Robux on Reaper Follow — if it exists, it covers the same core benefit for free.
Is Reaper Follow worth buying?
No source checked for this page describes Reaper Follow as required to progress — it's consistently framed as convenience, not power. If you play in short sessions, or the in-game portal shortcut mentioned above works for you, there's no confirmed reason you need it. If you play long sessions and want to skip manual travel entirely, it's a reasonable quality-of-life purchase per gamestratwiki's own framing.