The option to use the word that in a sentence is a tricky one. Some say it helps understanding, others argue it hurts. Reporters, traditionally short on space, tend to leave it out. This is a roundup of advice from various style guides (with their examples omitted).
Specifically, Canadian Press Style Book says:
Dropping that often makes for smoother reading, especially in shorter sentences. But retain it to avoid misleading the reader even momentarily. That should also be retained and repeated with two or more clauses.
And the 2024 American Press Stylebook says:
Use the conjunction that to introduce a dependent clause, if the sentence sounds or looks awkward without it. There are no hard-and-fast rules, but in general:
– That usually may be omitted when it dependent clause immediately follows a form of the verb to say
– That should be used when a time element intervenes between the verb and the dependent clause.
– That usually is necessary after some verbs. They include advocate, assert, contend, declare, estimate, make clear, point out, propose, and state.
– That is required before subordinate clauses beginning with conjunctions such as after, although, because, before, in addition to, until and while.
When in doubt, includes that. Omission can hurt. Inclusion never does.