Why is RFK Jr. entitled to Secret Service Protection?

Campaign 2024 - Candidate Protection
https://www.secretservice.gov/protection/leaders/campaign-2024

Only certain candidates are entitled to Secret Service protection. It is not up to the Secret Service.

Title 18 U.S.C.' 3056(a)(7) authorizes the U.S. Secret Service to provide protection for major Presidential and Vice Presidential candidates:

Protection is authorized by the DHS Secretary after consultation with the Congressional Advisory Committee;
The Congressional Advisory Committee includes: Speaker of the House, House Minority Leader, Senate Majority Leader, Senate Minority Leader, and one additional member selected by the others;
Protection under these guidelines should only be granted within one year prior to the general election. Protection more than one year prior to the general election should only be granted in extraordinary, case by case circumstances in consultation with the committee, based on threat assessment and other factors.

Criteria have been established to assist the DHS Secretary and the advisory committee in their decision making (as of 2017).

When determining whether a candidate for the Office of President or Vice President of the United States qualifies as a major candidate, the Secretary has broad discretion and may consider a variety of factors. These factors include, but are not limited to: .....

Whether the candidate is the formal or de facto nominee of a major party for President or Vice President;
Whether the candidate is an independent or third-party candidate for President polling at 20% or more of the Real Clear Politics National Average for 30 consecutive days;
Whether the candidate is the Vice Presidential running mate of the above independent or third-party candidate.