It's not a proper report as stated
"The matters covered by our Inquiry are highly sensitive. We have been told, repeatedly, that the Russian Intelligence Services will analyse whatever we put in the public domain and therefore, on this subject more than any other, the potential to damage the capabilities of the intelligence and security Agencies and Defence Intelligence was both real and significant. It was clear, therefore, that any Report would have to be subjected to extensive redaction, and risked becoming unreadable. In order to be able to publish a Report at all, we have accordingly decided to produce a shorter Report than usual, which takes the form of a summary of the most important points we have noted during the Inquiry, at a high level, without revealing underlying detail. We have supplemented this with a substantial Annex, which provides both greater detail on the points we have raised and further rationale for the judgements we have reached. This Annex is not published at this time, in view of the current Russian threat."
Also
"47. We have not been provided with any post-referendum assessment of Russian attempts at interference, ***.53 This situation is in stark contrast to the US handling of allegations of Russian interference in the 2016 presidential election, where an intelligence community assessment54 was produced within two months of the vote, with an unclassified summary being made public. Whilst the issues at stake in the EU referendum campaign are less clearcut, it is nonetheless the Committee’s view that the UK Intelligence Community should produce an analogous assessment of potential Russian interference in the EU referendum and that an unclassified summary of it be published.55"
Shows there was a distinct lack of any attempt to look into this by the government, wonder why.
Also
"The Government recognises that the increase in demand for intelligence to support the campaign against terrorism has meant that the Agencies, amongst others, have been obliged to review their priorities within their own budgets. This process has been carried out professionally and carefully, and the Government will continue to keep the situation under review. It is inevitable that if some areas of activity become relatively more important to the national interest, others become relatively less so and may have less resources devoted to them. All decisions about matching resources to tasks involve a degree of risk. Identifying, quantifying, managing, and where possible mitigating those risks is one of the basic responsibilities of the management of the Agencies. The Government is confident that the judgements taken so far have been the right ones, and that no unacceptable risks with or to national security have been, or will be taken.67"
Reduce budget to investigate in case you find something incriminating